# Did I bust a bearing?



## -wizpip- (Sep 20, 2011)

Or something else?

YOU DECIDE. (And then I'll tell you what the TT shop says).


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## Hoggy (May 8, 2002)

Hi, Something in a Tyre ?
Hoggy.


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## -wizpip- (Sep 20, 2011)

Hoggy said:


> Hi, Something in a Tyre ?
> Hoggy.


Ha! I wish. Sounds much more expensive to me  Wouldn't surprise me if I picked up that screw when I pulled over [smiley=bigcry.gif]


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## Hoggy (May 8, 2002)

Hi, Is it till drivable ?
Hoggy.


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## -wizpip- (Sep 20, 2011)

Hoggy said:


> Hi, Is it till drivable ?
> Hoggy.


I pulled off after this, and the sound dissipated somewhat. It's almost disappeared completely, but there's still a faint grinding noise between 10 - 20mph. And occasionally acceleration now sounds like a bus. Other than that, the drive feels fine.

If I had to guess, I'd say one of the balls exploded inside the bearing and spread itself around the casing.


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## rajanm1 (Feb 1, 2014)

What did the ttshop say?


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## -wizpip- (Sep 20, 2011)

rajanm1 said:


> What did the ttshop say?


You've jumped the gun a bit, it's not there yet!


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## tttony (Dec 21, 2014)

It is very rare for a ball to "explode". The usual failures are either track break up on either the inner or outer races, or disintegration of the cage that hold the balls. The causes can be lack of lubrication, poor quality bearing or just plain wear. It would be very unusual for an Audi OEM quality bearing to fail before a very high mileage unless it was a rouge one that slipped through its manufacturers QC.


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## Stealth69 (Jun 25, 2012)

Doubt it's a bearing, you'd have known a bit more about it at that speed........ is the sound there when stationary ? can you get a video of the engine sat still? (bonnet up and engine running obviously LOL)


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## -wizpip- (Sep 20, 2011)

Stealth69 said:


> Doubt it's a bearing, you'd have known a bit more about it at that speed........ is the sound there when stationary ? can you get a video of the engine sat still? (bonnet up and engine running obviously LOL)


For your viewing pleasure...

Ignition, idle, then after it calms down I revved it a bit (at about 1:50).


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## -wizpip- (Sep 20, 2011)

It's booked into the TT shop for Thursday. One thing I noticed today when I took it for a short trip to the post office is that the grinding is variable. It seems louder today, and the 'bus' noise only seems to happen during acceleration in 3rd and 4th. But when it's not accelerating, no bus sound.

I did have some new Haldex and S-Tronic oil recently, and if it's not bearings then maybe it's in these more expensive bits.


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## -wizpip- (Sep 20, 2011)

-wizpip- said:


> I did have some new Haldex and S-Tronic oil recently, and if it's not bearings then maybe it's in these more expensive bits.


I forgot to mention, after I pulled away from the event I got a TPMS error on the dashboard, though this went away then the car was next stopped and started and hasn't returned.

So, place your bets on which part of the transmission has gone a bit wrong!


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## C00P5TT5 (Jul 10, 2016)

Obvious I know but have you checked all the wheel nuts are tight and in one piece?


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## -wizpip- (Sep 20, 2011)

P1723944 said:


> Obvious I know but have you checked all the wheel nuts are tight and in one piece?


I spent a while going around the whole car. There's nothing visibly wrong with it. And I don't have a proper jack to be able to test the stability of the wheels and their hubs, alas.


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## C00P5TT5 (Jul 10, 2016)

I'd be really interested in finding out what it turns out to be if i was a betting man my money would be on a wheel bearing. Good luck with it and keep us posted


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## C00P5TT5 (Jul 10, 2016)

Or differential, can i spread my bet


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## -wizpip- (Sep 20, 2011)

P1723944 said:


> Or differential, can i spread my bet


You may, but the diff might require me to take out a small loan!


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## C00P5TT5 (Jul 10, 2016)

mmm know that feeling. Out of interest how many miles has it done, are the wheels standard?


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## -wizpip- (Sep 20, 2011)

P1723944 said:


> mmm know that feeling. Out of interest how many miles has it done, are the wheels standard?


Everything is standard, it's done about 114k miles. But I was rear-ended at 82k miles, so all of this is only 30k miles old:

Guide No. Description Part Number Bet. Held Date Price
2581 REAR BUMPER 8J0 807 303 E GRU 0% £357.92
2604 RR LWR BUMPER COVER 8J0 807 421 F 1RR 0% £81.31
2605 REAR BUMPER SPOILER 8J0 807 514 X7W 0% £0.00
2617 L/R BUMPER GUIDE 8J0 807 453 B 0% £6.30
2618 R/R BUMPER GUIDE 8J0 807 454 B 0% £6.30
2619 L/R OUT BUMPER GUIDE 8J0 807 483 A 0% £6.30
2620 R/R OUT BUMPER GUIDE 8J0 807 484 A 0% £6.30
2621 L/R INN BUMPER BRKT 8J0 807 773 0% £8.27
2622 R/R INN BUMPER BRKT 8J0 807 773 0% £8.27
2640 REAR BUMPER SUPPORT 8J0 807 309 0% £109.00
2643 REAR BUMPER DAMPER 8J0 807 695 0% £18.30
2650 RR BUMPER CLAMP KIT 0% £18.13 *
2655 REAR BUMPER CLIP N 910 383 01 06X 0% £0.00
2656 REAR BUMPER CLIP N 106 213 01 10X 0% £0.00
2711 REAR PANEL 8J0 813 331 C 0% £48.74
2719 REAR PANEL C-MEMBER 8J0 813 307 C 0% £40.75
3281 L/R LAMP 8J0 945 095 G 0% £107.63
3282 R/R LAMP 8J0 945 096 G 0% £107.63
3403 R/FOG LAMP 8J0 945 703 0% £34.98
3901 BOOTFLOOR 8J8 813 101 F 0% £306.08
4057 FUEL TANK 8J0 201 060 N 0% £312.36
4067 FILLER HOUSING 8J0 809 933 E 0% £3.66
4074 FUEL FILLER CAP 8J0 201 550 G 0% £18.77
4095 FUEL TANK PROTECTION 8J0 201 307 C 0% £36.82
4201 L/R WHEELHOUSE COVER 8J0 810 171 E 0% £32.86
4202 R/R WHEELHOUSE CVR 8J0 810 172 E 0% £32.86
8795 FRT CTR EXHAUST PIPE 8J0 254 502 LX 0% £908.58
8833 RR EXHAUST SILENCER 8J0 253 181 BA 0% £826.09
8836 REAR HEAT SHIELD 8J0 825 711 G 0% £30.66
8841 REAR SILENCER CLAMP 1K0 253 141 H 0% £14.02
8844 RR EXHAUST FRT BRKT 1K0 253 144 AP 0% £18.58
9081 REAR SUPPORT FRAME 5N0 505 235 AG 0% £322.58
9201 L/R SHOCK ABSORBER 8J0 513 029 Q 0% £69.64
9202 R/R SHOCK ABSORBER 8J0 513 029 Q 0% £69.64
9231 L/S-ABSORB SUPPORT 3C0 513 353 C 0% £22.05
9232 R/S-ABSORB SUPPORT 3C0 513 353 C 0% £22.05
9305 L/R WHEEL BRG HSG 3C0 505 433 G 0% £244.82
9375 L/R TIE ROD 1K0 501 529 J 0% £46.82
9383 L/R AXLE STEERING 1K0 505 223 K 0% £87.87
9384 R/R AXLE STEERING 1K0 505 224 K 0% £87.87
9385 L/R LWR CONTROL ARM 1K0 505 311 AB 0% £72.61
9386 R/R LWR CONTROL ARM 1K0 505 311 AB 0% £72.61
9387 L/R UPP CONTROL ARM 5Q0 505 323 C 0% £72.28
9551 L/R WHEEL 8J0 601 025 CM 0% £551.02
9565 L/R TYRE 0% £213.12 *
9566 R/R TYRE 0% £213.12 *
9627 BATTERY 12V 72AH 000 915 105 DG 0% £112.25
1000 CAR CARE PACK Renew 0% £5.00 *
1000 SOUND PAD X1 Renew 0% £7.00 *
1000 PNL SEALER/DOOR ETC Renew 0% £8.00 *
1000 SPOT WELD DRILL Renew 0% £2.50 *
1000 HEAVY STONE GUARD D003500 0% £18.00 *
1000 BRAKE FLUID Renew 0% £12.00 *
1000 REAR DAMPER SENSORS Renew 0% £0.00
1000 RR DAMPER SNSR PLUG Renew 0% £0.00

Alas, none of that is expensive moving parts.

And if you're curious what that cost to fix with the labour and VAT...
Grand Total Incl VAT £10,674.54

The other car was a Porsche.

If that happened at my current mileage I'm sure it'd be a write-off.


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## C00P5TT5 (Jul 10, 2016)

Ah so it's been in a smash, that for me explains it, with that amount of damage it will never be the same. Pin it on the insurance company they have obviously not put everything right, which in there defence how could they. Something in that smash has either not been addressed or now gone wrong.

Keep us updated though


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## -wizpip- (Sep 20, 2011)

P1723944 said:


> Ah so it's been in a smash, that for me explains it, with that amount of damage it will never be the same. Pin it on the insurance company they have obviously not put everything right, which in there defence how could they. Something in that smash has either not been addressed or now gone wrong.
> 
> Keep us updated though


You say that, but my first S-Tronic blew up all on its own pre accidents and was warrantied... It's difficult to attribute it to any specific cause I suspect.


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## GaryG (Aug 21, 2016)

£5 on damage to exhaust downpipe + an each-way R/N/S tyre - an 'egg' on the tread and flapping under engine guard.


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## C00P5TT5 (Jul 10, 2016)

Nail in the tyre, nail in the tyre!

Just seen the other thread. Going all in on the nail in the tyre....guna clean up!


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## -wizpip- (Sep 20, 2011)

P1723944 said:


> Nail in the tyre, nail in the tyre!
> 
> Just seen the other thread. Going all in on the nail in the tyre....guna clean up!


Whilst I'd love that to be true, I doubt picking up a screw at 70 would make the car jump with 2G of force, and then make a grinding noise... I suspect there's a bit more clearance for the wheels than that :wink:


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## C00P5TT5 (Jul 10, 2016)

It's almost like the dealer showed his hand before the bets were placed.

This great fun betting on others misfortune, any chance the forum can obtain a gambling licence?

Sorry fella, but this really wants me to find out what is wrong. Keep us posted


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## C00P5TT5 (Jul 10, 2016)

Maybe the screw was attached to something before it got attached to your ride.

Is it still in there?


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## -wizpip- (Sep 20, 2011)

P1723944 said:


> Maybe the screw was attached to something before it got attached to your ride.
> 
> Is it still in there?


It is. I'm relatively sure that the underneath of a car only uses bolts though


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## C00P5TT5 (Jul 10, 2016)

I was thinking more that you ran over something. Either way the angle which it's in will surely make some sort of noise whe the wheel spins. And i suspect the fast you go the loader it would get.

Still betting on the nail.

When will you find out the suspence is killing me!


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## -wizpip- (Sep 20, 2011)

P1723944 said:


> When will you find out the suspence is killing me!


They're looking at it tomorrow!


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## brittan (May 18, 2007)

Broken engine mount - on the nose.


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## -wizpip- (Sep 20, 2011)

brittan said:


> Broken engine mount - on the nose.


Wouldn't you have expected more movement from the engine in this video? https://www.youtube.com/watch?v=4pQj0Jl ... e=youtu.be


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## brittan (May 18, 2007)

-wizpip- said:


> Wouldn't you have expected more movement from the engine in this video? https://www.youtube.com/watch?v=4pQj0Jl ... e=youtu.be


Ah, didn't see that before.

Someone has sneaked a bag of nails under your bonnet.


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## C00P5TT5 (Jul 10, 2016)

Wo, wo, wo brittan the bet has been placed you can't back out.....Where's the floor manger.

Tbh looking at wizpip other thread and the bad luck he's had with this car it could be bloody anything.

Is it too late to put a checky fiver on a dead badger wedged in the wheel arch?


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## -wizpip- (Sep 20, 2011)

P1723944 said:


> Is it too late to put a checky fiver on a dead badger wedged in the wheel arch?


Maybe I hit someone from MI6 testing out a new invisibility device, and their invisible corpse is mangled around the underneath of the car?


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## C00P5TT5 (Jul 10, 2016)

Gota say you have a great sense of humour and this thread is comedy......I really hope it's something not major


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## John-H (Jul 13, 2005)

Sounds like low oil pressure :?


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## -wizpip- (Sep 20, 2011)

Just had a call back from the TT Shop...

... they want more time to look at it. So no finding out what's wrong with it today. [smiley=book2.gif]


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## John-H (Jul 13, 2005)

Now I've listened to it on my PC without the loud background the engine doesn't sound too bad but the whirring noise sounds like a tight cam belt. Not sure if that's likely. Not oil pressure like my phone seemed to be telling me. The driving video is more violent - like a CV joint falling apart. Odd that it seems to have fixed itself somewhat. Good luck finding it.


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## C00P5TT5 (Jul 10, 2016)

Oh no, this does not sound good....did you show them the nail in the tyre.... It's not something they would instantly look for?

Joking aside I hope it not too bad....funny thing is I had a ka before I got a tts and I said to myself I won't show it no attention, run it into the ground then I can justify buying a new car to the miss's..... Bloody thing past every mot, never broke down. ..in the end i sold it and told her it had been stolen


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## -wizpip- (Sep 20, 2011)

P1723944 said:


> in the end i sold it and told her it had been stolen


 :lol:

The guy in Bedford Audi smirked at my Ka and called it a "Fix Or Repair Daily", but it too never had any issues.

I told the TT Shop about the screw, but I guess they want to find the actual problem before they tell me how much it's all going to cost to go away [smiley=bigcry.gif]


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## -wizpip- (Sep 20, 2011)

Hmm, no call from the TT Shop today, and they've not picked up the phone...

I hope my car hasn't exploded / given them all depression / etc.

Still haven't been told what's wrong with it :?


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## John-H (Jul 13, 2005)

We are on tenterhooks. . . 
(an interesting phrase derived from the wool industry ;o) http://www.phrases.org.uk/meanings/on-tenterhooks.html


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## C00P5TT5 (Jul 10, 2016)

Oh my god!!!!!!
Please tell me they are open on weekends. I need to know whats causing that noise


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## TT-driver (Sep 14, 2010)

Is the casino still open, or is it rien ne va plus?

A failed suspension part and now something is rubbing against a tyre !


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## -wizpip- (Sep 20, 2011)

Sure is. I think they've been a bit busy, I got this email:



> Having inspected the car there is some damage to the underside of the car.
> 
> We will be getting it back on a ramp next week to do further investigation, but advise it should not be driven until we can fully assess it.


 [smiley=gossip.gif]


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## brianmcc51 (Oct 4, 2014)

Any update on this ?


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## -wizpip- (Sep 20, 2011)

brianmcc51 said:


> Any update on this ?


Heard nothing on Monday, Tuesday they wanted me to come in. Going to show me something on the ramp today...


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## C00P5TT5 (Jul 10, 2016)

Take some pictures and post them on here?


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## Dash (Oct 5, 2008)

Pictures of the badger?


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## C00P5TT5 (Jul 10, 2016)

Nail, badger what ever pays out on the bet I've placed


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## -wizpip- (Sep 20, 2011)

P1723944 said:


> Or differential, can i spread my bet


You win, sir. More details to follow.


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## C00P5TT5 (Jul 10, 2016)

Get in! I can now take early retirement.

So it's the diff, sorry to hear that my friend, is it's guna cost?

I would like to donate my winnings to fix your car rather than retire.

Keep us updated


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## -wizpip- (Sep 20, 2011)

P1723944 said:


> Get in! I can now take early retirement.
> 
> So it's the diff, sorry to hear that my friend, is it's guna cost?
> 
> ...


I don't think you won enough.

http://www.genuineautoparts.com/uk/parts/audi-carrier-assembly-0br525010g


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## C00P5TT5 (Jul 10, 2016)

Oh....well we know what's going on your Christmas list.

Any idea what caused it?
Really feel for you, and congratulations on the award for the best post ever, I've been checking every day for updates


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## C00P5TT5 (Jul 10, 2016)

Would a second hand diff be an option?


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## -wizpip- (Sep 20, 2011)

P1723944 said:


> Any idea what caused it?


I'm going to say that although I didn't see anything, something must have hit my back wheel and stressed the diff. Would explain why the car jumped and why there's an incredibly unlikely screw in the tyre!

When they get the diff off I'll take some photos of it (which aren't all blurry) and the insides if I can...



> Would a second hand diff be an option?


I'm looking into options at the moment. So are the garage!


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## C00P5TT5 (Jul 10, 2016)

I knew the nail would have a part to play in this unfortunate chain of events!


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## C00P5TT5 (Jul 10, 2016)

Will your insurance cover it? If you have run over something on the motorway that could have caused a major accident is that not a claim against the highway agency?


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## C00P5TT5 (Jul 10, 2016)

Sounds like something feel off a flat bed truck that you have come into contact with, but i guess unless you know what truck it was you might be screwed


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## -wizpip- (Sep 20, 2011)

P1723944 said:


> Sounds like something feel off a flat bed truck that you have come into contact with, but i guess unless you know what truck it was you might be screwed


Sometimes I wonder if my car fell off a flatbed truck!


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## C00P5TT5 (Jul 10, 2016)

I like you winzip even in the jaws of despair you have a sense of humour.

I official start the winzip diff charity fund


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## C00P5TT5 (Jul 10, 2016)

Let's start tin rattling


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## C00P5TT5 (Jul 10, 2016)

Tokens, tokens please..... Oh no that's a different websites


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## GaryG (Aug 21, 2016)

-wizpip- said:


> I don't think you won enough.
> 
> http://www.genuineautoparts.com/uk/parts/audi-carrier-assembly-0br525010g


Aaaarrrrgggh! I might be able to stretch towards the price of the new O ring...

Did the casing break?


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## -wizpip- (Sep 20, 2011)

GaryG said:


> Did the casing break?


It has a crack bigger than me


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## hooting_owl (Sep 3, 2008)

Your crack will be much bigger by the time it is fixed. I feel for you....


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## brittan (May 18, 2007)

Not the first broken diff seen on here but certainly a serious wallet denting incident.
viewtopic.php?f=19&t=381074&p=4674769&hilit=diff+broken#p4674769

Seems the cast aluminium casing doesn't like shock loads.


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## TT-driver (Sep 14, 2010)

It seems the diff may house a little terrorist sometimes:

viewtopic.php?f=19&t=189507


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## GaryG (Aug 21, 2016)

brittan said:


> Not the first broken diff seen on here but certainly a serious wallet denting incident.
> viewtopic.php?f=19&t=381074&p=4674769&hilit=diff+broken#p4674769


The thing is that the video by wizpip does not show anything in the road that would have caused the damage and that previous thread blames the oil (or lack of it) in the diff.

As suggested in the earlier thread, I would try the insurance company and see if they accept the accidental damage or try to avoid responsibility by claiming that it was failure caused by negligence as to the oil in the diff. If the latter, the challenge will be to show that the diff did not receive a blow and that the oil was the wrong type.

The next question is "Who owned the car when the oil was put in?" If it was the previous owner, not much can be done. If it leaked out after being put in in wizpip's ownership, that's probably bad luck, If there is no leak and no blow and the wrong 
oil was changed/added to in wizpip's ownership, the garage will be liable and insured.


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## -wizpip- (Sep 20, 2011)

GaryG said:


> The next question is "Who owned the car when the oil was put in?" If it was the previous owner, not much can be done. If it leaked out after being put in in wizpip's ownership, that's probably bad luck, If there is no leak and no blow and the wrong oil was changed/added to in wizpip's ownership, the garage will be liable and insured.


I've owned it from new. The S-Tronic and Haldex oil were both changed by the TT Shop on the 7th of October. Where does the diff oil come from?


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## -wizpip- (Sep 20, 2011)

Hmm, after they did the oil changes I went back shortly after to say there was a sound occasionally that was like a motorbike pulling away behind me as I did, a whining sort of sound. I thought it may be a coincidence, but reading some of these other threads, they seem to suggest the whining is the diff, which is one hell of a coincidence for it to start as soon as the oil is changed in the other components.

Do you think they did it wrong? There's literally no way I'm going to be able to prove that.


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## -wizpip- (Sep 20, 2011)

My Google tracking tells me that after picking the car up on the 7th, I returned on the 18th for them to listen to the sound, which they didn't think was present or unusual. In fairness, it was pretty faint and somewhat intermittent.

The car has done 114k miles, so what would you do... blame the garage, or put it down to age / coincidence and claim on insurance if possible... etc?


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## TT-driver (Sep 14, 2010)

After 114k miles of faultless functioning, I'd say there is no chance that there was a fault in the parts/materials used. 
If the car was driving with the wrong oil or not enough oil I'd expect to see some sort of heat development on the cogs. At some stage the parts must have been welded together and broken loose again. At least something like that could explain the bump. You didn't have a new tyre on one side and a completely worn one on the other, did you?

I also checked the video carefully and couldn't see anything on the road that could explain for damage done from the outside. 
The whining noise... not a good sign either....


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## -wizpip- (Sep 20, 2011)

TT-driver said:


> You didn't have a new tyre on one side and a completely worn one on the other, did you?


All four tyres were changed at the same time and have been on the for at least 10k miles...


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## brittan (May 18, 2007)

I've never had diff failure on any car but I have repaired/rebuilt many Land Rover and Range Rover diffs - all damaged/broken by shock loading.

A whining diff would point to lack of lubrication, severe wear or incorrect meshing depth on the crown wheel and pinion gear teeth. The latter two items would not have happened in the short time after the oil changes which leaves lubrication, or its lack. Surely however the TT Shop would not have failed to refill the diff or put in Haldex oil, which is a thin hydraulic type fluid rather than an EP oil. Surely?

The cracked diff casing could easily have been the result of attempted escape by the internals following breakage.

This sounds remarkably similar: http://www.honestjohn.co.uk/user-articl ... -tt---audi but describes changing only the Haldex oil, no mention of diff oil change.


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## brittan (May 18, 2007)

Just a thought: there may be insufficient oil left in the diff to get a sample for analysis but you could carry out the same exercise on the Haldex unit.


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## -wizpip- (Sep 20, 2011)

brittan said:


> A whining diff would point to lack of lubrication, severe wear or incorrect meshing depth on the crown wheel and pinion gear teeth. The latter two items would not have happened in the short time after the oil changes which leaves lubrication, or its lack. Surely however the TT Shop would not have failed to refill the diff or put in Haldex oil, which is a thin hydraulic type fluid rather than an EP oil. Surely?


Wouldn't have thought so, but the whining started straight afterwards, and the diff blew within 200 miles. But they already told me the diff oil is different and they didn't touch it, so I guess I need to pay for a new diff by myself


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## -wizpip- (Sep 20, 2011)

I mean, I do think it's unlikely that the TT Shop did something wrong to a TT...

Testing the oil is only going to make them hate me :lol:


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## brittan (May 18, 2007)

Yes, was just re-reading and saw you had Haldex and S-Tronic oil changes and not Haldex and diff.

My thought on a possible failure mechanism, admittedly rather fanciful, was that diff oil was put in the Haldex unit; that meant that the unit would not allow slip when it should; that caused transmission wind up between front and rear axles and the rear diff was the weak point.



-wizpip- said:


> I mean, I do think it's unlikely that the TT Shop did something wrong to a TT...
> 
> Testing the oil is only going to make them hate me :lol:


Unlikely - yes. Possible . . . . .

Testing the oil could save a lot of money. Something caused that catastrophic failure and you don't know what yet.


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## -wizpip- (Sep 20, 2011)

brittan said:


> Testing the oil could save a lot of money. Something caused that catastrophic failure and you don't know what yet.


True...

I'm actually just back from there, I live within walking distance so went for a little chat about how to proceed. Dave mentioned that the Haldex unit still had all of its oil, and that the oil dripping out of the diff smelt like burnt clutch.

And they'll be insured, so I wouldn't think there's any reason they'd need to lie about it. Although, I wouldn't put it past the dealership who would have last changed the diff oil to have done it wrong. When does the diff oil get changed?


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## brittan (May 18, 2007)

I could easily be on entirely the wrong track but the Haldex oil check would also be one to eliminate a (remote) possibility. 
It should be easy enough to confirm the oil is correct just by sight/smell/feel.

Burnt diff oil suggests overheating for some reason. Could the diff oil have escaped? A strip down will give some clues but the 2g jump points more to a debris strike, though none seen in the video, or breakage of the diff internals.

Audi do not list an oil change interval for the diffs or the manual gearbox.


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## -wizpip- (Sep 20, 2011)

I'm assuming it blew up on the inside, then leaked its stuff everywhere. Although, it was whiny for 200mi right after my haldex change before it blew up.

Dave did say that my shafts looked ok.

There's a crack all along that bottom fin and what looks like a hole in the depression, although I haven't been able to find another image of the same diff at this angle to determine if that's normal or not.


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## TT-driver (Sep 14, 2010)

Ok so not the tyres. Two other thoughts (admitting I'm not familiar with this diff)

1) isn't there an oil filter in that thing? Could it be it was mounted in such a way that the diff doesn't get any lubrication?

2) are there electronics involved? Could it be the diff was engaged more than it is designed to do?

If I sound stupid, I'll get my coat. :wink:


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## GaryG (Aug 21, 2016)

If it's any compensation, what with the tyre and then this, you are posting some of the most interesting photos I've seen.

The resolution of the diff photo is excellent. There's no sign of anything having hit it, but there seems to be two cracks - one on either side of the rib. There is no visible crack across the rib. The crack on the left seems wider but has leaked less oil. (Is there another (vertical to the photo) crack directly below it?)

The one on the left seems to have been leaking small amounts of oil for a while - the one on the right seems more recent and to have leaked a little more but still not much.

I could guess that the right crack opened a little when under power and oil was lost - but that leaves the question of why the crack is there in the first place. It could be a duff casting or, and less likely, interior damage.


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## -wizpip- (Sep 20, 2011)

GaryG said:


> There is no visible crack across the rib.


I couldn't quite get it to focus fully on the crack whilst I was there so it's a bit hard to tell, but that bump on the rib isn't an oil bead - that's where the crack joins together... Given the jolt the car suffered I'd be highly surprised if there wasn't something a bit mashed up in there!

I'm a web developer for a living, so I try not to let 1MB file limits stop me posting huge photos. As it happens, a high resolution image saved as a low quality JPG has more detail than an image with the same filesize but lower resolution and higher quality...

Here's an image I've enhanced slightly to show the crack passing over the rib. Still not massively clear, but slightly clearer than the other one on that rib...


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## -wizpip- (Sep 20, 2011)

Hang on, this may help. I think that's supposed to be a straight line...


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## GaryG (Aug 21, 2016)

Well done! I see it now. Horrible! There was some force went into that.

You're not alone: http://www.audi-sport.net/xf/threads/20 ... re.147234/

On the subject of oil: http://workshop-manuals.com/audi/tt_roa ... turbo_(bpy)/transmission_and_drivetrain/differential_assembly/fluid_differential/component_information/service_and_repair/axle_oil_level_in_rear_final_drive/page_4176/


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## -wizpip- (Sep 20, 2011)

GaryG said:


> You're not alone: http://www.audi-sport.net/xf/threads/20 ... re.147234/


It's a shame there's no follow up to that story - mine was exactly 200 miles as well!


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## -wizpip- (Sep 20, 2011)

You know, I just did a Google for "Audi differential crack".

I should have done it before. In the first three pages, I found all these. All but one exploded after a haldex change. (one or two have already been linked to by others on this thread)

http://forums.vwvortex.com/showthread.php?6897488-rear-diff-lockup-causes
http://www.vwaudiforum.co.uk/forum/showthread.php/38881-A3-2-0tdi-cracked-rear-diff
http://www.audi-sport.net/xf/threads/another-bad-differential-on-an-audi-tt.197307/
http://www.audizine.com/forum/showthread.php/455138-Cracked-rear-differential!
http://www.ttforum.co.uk/forum/viewtopic.php?f=19&t=189507
http://www.honestjohn.co.uk/user-article/114786/audi-tt---audi
http://www.audi-sport.net/xf/threads/2008-tt-quattro-rear-differential-failure.147234/

Only one of them conclusively states that the dealership admitted to doing the haldex wrong, which was the cause of the issue. But that's enough of an admission to make me curious.


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## -wizpip- (Sep 20, 2011)

There are at least three people on this thread that all commented when their diff blew up, coincidentally after a haldex change. None are sure if it was a tech fault or some weird pressure imbalance / blockage.

http://www.r32oc.com/topic/21716-catastrophic-rear-axle-failure/


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## -wizpip- (Sep 20, 2011)

TT-driver said:


> The whining noise... not a good sign either....


In my current Googling mood, at least one of the posts I mentioned earlier suggests that whining could be, rather than the wrong oil: a lack of it.

Indeed, vehiclemd.com suggests that:
Whine - A constant whine when the car is in motion could indicate worn gears in the driveline, usually in the differential. It could also mean the differential fluid needs to be replaced.

So, how likely does this scenario sound:

Haldex oil is changed, correctly. Diff oil is accidentally drained and left empty, or near empty.
Car is slightly whiny. Although demoed to garage, it's not really noticeable at the time.
On a 100 mile trip, after 80 miles at almost 70mph continuously, the diff gears expand from friction to the point where they cause the diff casing to crack, sending a shockwave through the chassis.

Of course, that'll be impossible to actually prove. Although if the casing cracked from expansion, it's entirely possible that all of the gears inside the diff are fine. Which would definitely point to overheating from lack of oil.


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## brittan (May 18, 2007)

-wizpip- said:


> So, how likely does this scenario sound:
> 
> Haldex oil is changed, correctly. _etc etc_
> 
> Of course, that'll be impossible to actually prove.


The first step is as I already posted; check what oil is in the Haldex unit and confirm what Dave told you regarding the amount of oil.

There may be some marks on the diff drain and fill plugs, or they may show signs of having been cleaned, if the oil was drained. On the other hand the leaked oil may mask any such signs.


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## TT-driver (Sep 14, 2010)

-wizpip- said:


> In my current Googling mood, at least one of the posts I mentioned earlier suggests that whining could be, rather than the wrong oil: a lack of it.
> 
> Indeed, vehiclemd.com suggests that:
> Whine - A constant whine when the car is in motion could indicate worn gears in the driveline, usually in the differential. It could also mean the differential fluid needs to be replaced.
> ...


Pretty close. Most oils used in gears contain sulphur. It helps bonding the oil to the metal so metal to metal contact is avoided. Even after draining the oil from the haldex, some oil remains on the gears. That can be enough for the diff to function a little while longer. But then as the remaining oil breaks down under pressure and heat, metal to metal contact starts to occur, causing even more heat. Up to a point even where two parts are welded together. And since the car is moving on, this weld is broken again.

A neighbour of my parents once had his gear box oil replaced. Well actually it was only drained. The car still drove for a couple of days. Then shifting got increasingly difficult. Followed by a bang.

The light weight metals used for the casing of a diff or gearbox fracture quite easily if the force put to them is in the form of a shock. A shock occurs when gears weld together and break loose again.

Like Brittan suggests: oil analysis (if there is anything left) is a first step. But since the diff is now broken, a post mortem of the diff itself is due too. If the gears got really hot, signs of heat build up can be visible. The weld point should be visible. And the smell of burned oil should be there.

I'm pretty sure the service of the diff and its unfortunate ending are linked.

Some info on broken diffs: http://www.differentials.com/technical- ... e-analysis


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## brittan (May 18, 2007)

Given the number of links referencing diff failure following a Haldex oil change I'm a little sceptical about each of those oil changes being accompanied by an accidental diff oil drain with no refill.

Hence my repeated suggestion that the apparently full complement of oil in the Haldex unit is examined (or tested) to check that it is the correct oil as a first step.

Again as I've already posted, a diff strip down to see how it has failed would be useful but I realise that would potentially add extra costs compared to simply binning it and fitting a replacement.


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## GaryG (Aug 21, 2016)

In view of this from the workshop manual - I would phone Audi and ask them what happens if the wrong oil is put in the Haldex or diff:


> Allocation, oil fill and drain plugs
> 
> 
> 
> ...


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## brittan (May 18, 2007)

I've been doing that Google thing too and found some relevant stuff searching for "Haldex wrong oil".

This one is the closest to wizpip's story: http://www.r32oc.com/topic/40366-haldex ... hat-to-do/

In the opening post he refers to _shudder and to have rubbing noises coming from the rear of my car in the area of the differential_ which I would take as evidence of transmission wind up.
The story also confirms that the Haldex unit was refilled the wrong oil - 75w90 gear oil was used.

Towards the end of the story he says,_ " I noticed that when doing tight corner at low speed - according to the Haldex self study guide the Haldex will disengage when maneouvering at low speeds to avoid the typical 4-wheel distortion of the drive train. Even when by-passing all the sensors that control the Haldex (yaw rate, speed sensor etc.) by pulling the hand brake one click, I was not able to disengage the clutch."_

This clearly suggests that putting the wrong oil in the Haldex effectively locks it. I think the chap in this story was lucky to get away with the diff still intact.

Previously I posted this:


brittan said:


> My thought on a possible failure mechanism, admittedly rather fanciful, was that diff oil was put in the Haldex unit; that meant that the unit would not allow slip when it should; that caused transmission wind up between front and rear axles and the rear diff was the weak point.


Maybe it wasn't so fanciful after all.


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## TT-driver (Sep 14, 2010)

Very similar stories here:

http://tts-freunde.de/forum/index.php/T ... nterachse/

The diff has 2 chambers and needs 2 different types of oil. Haldex oil for the haldex part, normal transmission oil for the diff part. In this case, the Audi dealer managed to drain the diff part and had filled it with haldex oil. Clearly the diff wasn't lubricated properly. Rest of the story is very similar: noise eventually followed by something that felt like a blown tyre.


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## -wizpip- (Sep 20, 2011)

I'm feeling fairly confident that the cause of the diff blowing up now is directly related to the haldex oil change. Whether that's the wrong oil, an accidentally drained diff, or something else... but the car was fine / no noise before, then ended up with noise and shortly after that a blown diff. Too many similar stories for it to be coincidental or unrelated mechanical failure.

But if I have the haldex oil tested and it's the right oil, then what? Does anyone know what the haldex oil is supposed to be?


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## brittan (May 18, 2007)

From my Haldex oil change at Audi dealer, the oil part number is G055175A2. 
A quick search did not find any type or viscosity information.

If you don't have the Haldex oil tested and it's wrong, then what?


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## -wizpip- (Sep 20, 2011)

brittan said:


> If you don't have the Haldex oil tested and it's wrong, then what?


Fair point. I asked Audi on Twitter if they know about these sorts of issues, but they just tell me to take it to a dealership to look at. Ironically, I stopped using the dealership because they were a bit useless.


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## TT-driver (Sep 14, 2010)

You could check the oil in the diff first. So not the Haldex end, but the other end. It should be transmission oil. The sulphur content in transmission oil makes that it has a very specific smell. I think haldex oil is similar to wet clutch fluid. That most probably has a different smell to it.

So you could turn it the other way around: go to the garage. Check if new haldex oil has a different smell than new transmission oil. If so: great. Next: drain what ever oil is left from both diff chambers. Smell if the right oil is coming from the right chamber. If not, bingo!


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## brittan (May 18, 2007)

I posted some similar comments earlier


brittan said:


> It should be easy enough to confirm the oil is correct just by sight/smell/feel.


but the diff oil has been reported as smelling of burnt clutch.

It's still easy though as the oil in the Haldex is only 200 miles old. Compare oil from the Haldex with new diff oil.
Apart from smell they may even be different colours. I think the Haldex oil is a hydraulic type oil similar to the sort you'd find in a conventional, torque converter type auto gearbox.


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## -wizpip- (Sep 20, 2011)

Going to wander down tomorrow morning with the list of people I've found from the first few pages of Google who've blown up their VW Audi diff (same part) within a few weeks of having a haldex service. Not including me, that's 16 people.

I know 16 is a tiny drop in a sea of thousands, but even without searching for haldex it keeps popping up where a differential has cracked. Going to request an oil test whilst I'm there.


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## John-H (Jul 13, 2005)

The oil for diffs and Haldex comes in different containers and has different fill methods with a caulking gun measured cartridge for the Haldex injected vertically upwards with the diff and gearbox sideways with a crushable bottle with a bendy spout. It's hard to think of mixing these up. Haldex oil is thin and light transparent brown coloured whereas the diff oil is obviously thicker and I think a little darker if my memory is correct.


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## -wizpip- (Sep 20, 2011)

John-H said:


> It's hard to think of mixing these up.


I agree it's unlikely, but there are so many other reports of diff cracks after the haldex service that it must be directly related somehow.


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## John-H (Jul 13, 2005)

Do you know how soon after for these cases though? If they were all immediate then that would indicate something but could it just be people looking for a connection and the last thing transmission related they can remember is a Haldex service - as that's the only regular transmission type service - so they relate to it and mention it as happening before.

There are people running round with Haldex locking screws in place so the plates are locked all the time but they seem to survive.

I can see running out of oil in the diff will eventually wear it out but they usually get very noisy. I've had shock loading break diffs before where one of the idler cogs breaks off teeth or snaps in two and if the bits happen to fall in between the pinion and crown or where there's not enough clearance then you could get a bust casting.


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## -wizpip- (Sep 20, 2011)

John-H said:


> Do you know how soon after for these cases though?


In all of the cases including mine it's given as between 2 days and 3 weeks, from 50 miles up to a few hundred. In most cases the crack happened at speed (many said motorway and freeway). One was in the 40s.



John-H said:


> I can see running out of oil in the diff will eventually wear it out but they usually get very noisy.


Several people, me included, reported a whining noise that was new directly after the haldex change. Most of us had that checked but none of the garages found anything. A few people only heard a loud strange whine a few seconds before it cracked.

Almost all of those haldex services were done by a dealership. Most of them were within warranty (first haldex change typically) so the relevant forum thread went dead because there wasn't a financial implication involved.
One person managed to get a dealership to confess that they'd accidentally drained the diff after they had an internal investigation.
One guy took the car away to have the oil independently tested. They found 'the wrong oils' in the cavity (it wasn't that specific), but the dealership then wouldn't deal with him as they accused him of changing the oil himself - that's pretty harsh!
One guy bought a year old car with 1900 miles on the clock from a dealership, and the diff cracked 10 days later. One can only assume whether the dealer had serviced it before selling it, or whether the part itself was a defect.

The fact that several people reported a whine after the haldex service, me included, for a part then bolted onto the haldex to crack is mightily suspicious. Now, whether that's incorrect oils or enthusiastic bolt tightening I don't know. Either way, I have strong reasons to suspect that the diff wouldn't have cracked if I hadn't had it serviced.


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## -wizpip- (Sep 20, 2011)

I've been to the garage this morning, and they're going to look into the list.

And I managed to find the service bulletin mentioned in this similar case:
http://www.ttforum.co.uk/forum/viewtopic.php?f=19&t=189507&start=15

Bulletin 2016846/4
https://www.scribd.com/doc/98849917/CasseHaldex-TSB2016846-4


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## brittan (May 18, 2007)

Google translate isn't very good, but nor am I. It gives this:
_Possible cause: The Haldex coupler and the transmission form a module with separate oil reserves. Within the oil change interval, confusion is often made between the drain and shut-off screws of the two systems due to the integrated construction of the Haldex coupler housing and the transmission.

In case of damage in the circumstances described below shortly after an oil change Haldex, an imputation in Guarantee and a Commercial participation are not possible.

The illustration shows the lower part of the gearbox housing.This irreparable damage occurs when differences in the rpm between the wheels can no longer be compensated. When the tires adhere properly, the kinematic chain tends so that the casing explodes at the angular control of the rear axle._

The bulletin picture shows the bottom of a gearbox. I'm not sure if the translation "_angular control of the rear axle_" means rear diff or the bevel gearing that takes drive to the front end of the prop shaft.

The bulletin reads very similar to my previous thoughts on the failure mechanism: after the Haldex oil change the unit is no longer able to slip to allow for the different rotation speeds of the front and rear axles, and with no tyre slip transmission wind up eventually causes something to give - whether that is the rear diff or the bevel gearing doesn't matter. On a practical level it could be either. 


brittan said:


> My thought on a possible failure mechanism, admittedly rather fanciful, was that diff oil was put in the Haldex unit; that meant that the unit would not allow slip when it should; that caused transmission wind up between front and rear axles and the rear diff was the weak point.


The picture in the bulletin of the Mk2 Haldex/diff assembly clearly shows the separate side fill points for both parts. On the Mk2 Haldex, there's no need to shove a caulking gun up its bottom.


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## -wizpip- (Sep 20, 2011)

brittan said:


> Within the oil change interval, confusion is often made





brittan said:


> In case of damage in the circumstances described below shortly after an oil change Haldex, an imputation in Guarantee and a Commercial participation are not possible.


Those two statements are a classic "This happens all the time. We're not going to keep paying for it. The dealer can sort you from their own pocket, if you can prove it."


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## brittan (May 18, 2007)

-wizpip- said:


> Those two statements are a classic "This happens all the time. We're not going to keep paying for it. The dealer can sort you from their own pocket, if you can prove it."


If "this happens all the time" it surely must be due, at least in some part, to poor design by Audi, or Borg Warner or whoever owns Haldex now. 
Not knowing what you're working on must have some input to the failures too. I changed the diff oil on mine last year but I knew that there are two reservoirs in the unit, each containing a different oil. All I had to check beforehand was the positions of the relevant drain and filler plugs. Mind you, the diff drain and fill points are very small, only about 6mm dia so the tube on most squeezy bottles of oil doesn't fit. 
The there's the relationship between familiarity and contempt . . . .

I think you have a good amount of relevant evidence to back up the assertion that the Haldex oil change precipitated the diff failure - however it's all circumstantial so far. We all wait to hear the reaction from the TT Shop.


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## John-H (Jul 13, 2005)

That's interesting and I knew I should have added the rider "if it's the same as the Mk1" as regards the different fill methods. So there is scope for confusion with the Mk2 design?

What still seems odd though is that putting a thick oil in the Haldex which seems likely at most to give something similar to a permanent engagement - as if you had added a Haldex lock bolt which quite a few Mk1 owners use - can elevate the forces enough to crack the casing.

The peak forces should be no greater for the normal situation of expected extremes - where say, the front wheels are slipping, 100% Haldex lock is already engaged, the engine is pushing maximum torque and then the back wheels fall into a pot hole or similar causing a shock off/on load. The gears and casing should be able to handle that - so it's hard to see how driving down a smooth road would cause loading in excess of that.

If the Haldex was 100% permanently locked then there would be extra loads due to unequal travel of front and back which would result in excess wheel slip and skip on turns - so you could imagine this causing extra wear in the long term - but not an immediate catastrophe.

For an explosive reaction so soon after a locked Haldex condition seems to point to a weakness in the Mk2 design. Surely it would have happened in the modified Mk1 if we are simply considering the effect of locking the Haldex.

I've experienced two broken diffs but they were on an Escort rally car with 4.4 ratio diff over uneven ground with wheel spin on soft compound tyres - that broke teeth but the cast iron casing didn't suffer. Modern alloy casings shouldn't be a compromise here if they've been designed properly to cope with conditions.


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## TT-driver (Sep 14, 2010)

Basically Audi FR says to the dealers: Pay attention what you're doing. Read the manuals, where an Haldex oil change and a diff oil level check are described in great detail. If you (the dealer that is) mess up the job, Audi FR will not pay for the damage caused. No goodwill gesture, no warranty, nothing.

It doesn't really say that it happens all the time. It says the design of the haldex diff is such that a mistake is easily made. That's why they issued this bulletin.

And they explain that this damage is caused by tension build up in the drive chain. It's the rear diff that is then the weakest point.


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## -wizpip- (Sep 20, 2011)

TT-driver said:


> It doesn't really say that it happens all the time.


Not technically, but it must have happened enough for them to issue a bulletin about it!


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## brittan (May 18, 2007)

.


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## John-H (Jul 13, 2005)

brittan said:


> John-H said:
> 
> 
> > That's interesting and I knew I should have added the rider "if it's the same as the Mk1" as regards the different fill methods. So there is scope for confusion with the Mk2 design?
> ...


Just trying to be helpful with perspective from experience and engineering but with no manual covering the Mk2.

I wouldn't have expected the Mk2 to move backwards however.



brittan said:


> John-H said:
> 
> 
> > What still seems odd though is that putting a thick oil in the Haldex which seems likely at most to give something similar to a permanent engagement - as if you had added a Haldex lock bolt which quite a few Mk1 owners use - can elevate the forces enough to crack the casing.
> ...


That's exactly what you get with wheel slip on a Mk1 or with a blue sports controller that locks on full throttle but the bolt is far cheaper but didn't let off. I've not heard of anyone with a sports controller or the bolt experience an exploding diff though.



brittan said:


> John-H said:
> 
> 
> > The peak forces should be no greater for the normal situation of expected extremes - where say, the front wheels are slipping, 100% Haldex lock is already engaged, the engine is pushing maximum torque and then the back wheels fall into a pot hole or similar causing a shock off/on load. The gears and casing should be able to handle that - so it's hard to see how driving down a smooth road would cause loading in excess of that.
> ...


Not too concerned how it applies rear coupling. The point was that once fully engaged with low front traction and a shock loading to the rear (or front possibility) it should be able to cope with that peak load by design which will be greater than wind up forces although the forces are accumulate admittedly.



brittan said:


> John-H said:
> 
> 
> > If the Haldex was 100% permanently locked then there would be extra loads due to unequal travel of front and back which would result in excess wheel slip and skip on turns - so you could imagine this causing extra wear in the long term - but not an immediate catastrophe.
> ...


Well that would be a consideration certainly that should be factored into the design in respect of peak loads as they should consider all road / tyre conditions under a 100% locked Haldex situation. But this failure seems to be on a smooth road which perhaps indicates more off a wear issue perhaps coupled with a weakness.



brittan said:


> John-H said:
> 
> 
> > For an explosive reaction so soon after a locked Haldex condition seems to point to a weakness in the Mk2 design. Surely it would have happened in the modified Mk1 if we are simply considering the effect of locking the Haldex.
> ...


I've not heard of any.



brittan said:


> John-H said:
> 
> 
> > I've experienced two broken diffs but they were on an Escort rally car with 4.4 ratio diff over uneven ground with wheel spin on soft compound tyres - that broke teeth but the cast iron casing didn't suffer. Modern alloy casings shouldn't be a compromise here if they've been designed properly to cope with conditions.
> ...


I would expect them not to be as strong but they should core with expected shock loads.

When clearances widen the separating forces can increase on gears. That's usually accompanied by excess noise. Perhaps the casting design strength is Ok with unworn bearings but becomes marginal after some excess wear due to wind up loading. It could even be a thermal issue if loading was expected to be intermittent but became constant.

Not heard of it with the Mk1 though although I did wonder what the bolt boys might discover after a while.


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## TT-driver (Sep 14, 2010)

-wizpip- said:


> TT-driver said:
> 
> 
> > It doesn't really say that it happens all the time.
> ...


I guess so. When mechanics can't keep up with the boffins of Vorsprung durch Technik... a note can save a lot of money, hassle and frustration. [smiley=book2.gif]


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## brittan (May 18, 2007)

Sorry wizpip, I shouldn't have bothered with that long reply, doesn't help you, so it's now gone.


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## -wizpip- (Sep 20, 2011)

brittan said:


> Sorry wizpip, I shouldn't have bothered with that long reply, doesn't help you, so it's now gone.


All good discussion. I've learnt a lot over the past few days, such as how the wrong oil can make parts explode. Funny though, I have a friend who a few years ago complained his engine was making a funny noise for a few months. Turned out he had no oil. At all. Months. Thousands of miles.

The car was fine. Ridiculous.


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## John-H (Jul 13, 2005)

It might help understand what's going on. If there's accelerated wear due to constant wind up loading for example (there mention of some noise ) then it might help to check for play in the bearings if the wear signs are not themselves damaged beyond recognition.

I presume you intend to take any discovered evidence further?


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## -wizpip- (Sep 20, 2011)

John-H said:


> It might help understand what's going on. If there's accelerated wear due to constant wind up loading for example (there mention of some noise ) then it might help to check for play in the bearings if the wear signs are not themselves damaged beyond recognition.


Probably unrelated, but I just noticed that the diff cracked exactly when the car got to the apex of that hill it was climbing.

And yes, I'm waiting to hear back after giving them that list, but I'll definitely be requesting further investigation.


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## GaryG (Aug 21, 2016)

I don't know where you want to be with this, nor if the garage were negligent. If you want to pursue the matter for damages, at this stage you need to have the oils examined. You may thus wish to have a word with an expert witness: http://www.expertwitness.co.uk/SearchRe ... ertid=3438. (I don't know the man, and there are probably others around - I note he is about as far from Bedfordshire as you can get without leaving the country.) to find out what he can do, what you can do, and how much he charges.

(Others at https://www.jspubs.com/search/silisting ... N=96918038 This bloke is in London: https://www.jspubs.com/search/fulldets. ... JWL8MW64C4)

He will be able to give you an idea of the costs (a) to test the oils and (b) his costs. However, if tests on the oil are done and you do go ahead, the mere appearance of such a person at the garage may convince them. You should, if successful, be able to claim back the costs.

It is important that you do not take samples yourself before taking some advice on how to do this, or, if you do, you use the correct procedure to obtain them, have a witness to your actions, seal the the samples, mark them, and hand one sample of each oil to the garage.


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## -wizpip- (Sep 20, 2011)

GaryG said:


> I don't know where you want to be with this, nor if the garage were negligent. If you want to pursue the matter for damages, at this stage you need to have the oils examined. You may thus wish to have a word with an expert witness: http://www.expertwitness.co.uk/SearchRe ... ertid=3438. (I don't know the man, and there are probably others around - I note he is about as far from Bedfordshire as you can get without leaving the country.) to find out what he can do, what you can do, and how much he charges.


I did a quick search myself, and this chap kept popping up on various websites. I guess that means he's the best, and expensive. But you'd expect that when his name is Dr Calvert Stinton Ph.D., D.I.C., B.Sc., A.R.C.S., M.E.I., M.A.E., Q.D.R.

Since the TT Shop haven't communicated with me since I gave them the list, I've sent Dr Stinton an email.


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## C00P5TT5 (Jul 10, 2016)

Wizpip get the oil test results and if it proves faul play i vote we all turn up to the place that done it, park in front and menacingly toot our horns, flash our lights and rev our engines.....we will get justice wizpip....they can't pick of the heard.....plus it would be a good xmas meet!


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## -wizpip- (Sep 20, 2011)

P1723944 said:


> Wizpip get the oil test results and if it proves faul play i vote we all turn up to the place that done it, park in front and menacingly toot our horns, flash our lights and rev our engines.....we will get justice wizpip....they can't pick of the heard.....plus it would be a good xmas meet!


Ha, even if something is wrong with the oil, they wouldn't have done it with malice. And it's their prerogative to deny doing anything wrong until proven otherwise, because right now they'd genuinely not know.


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## C00P5TT5 (Jul 10, 2016)

True, your comment on malice...however I would argue due care and attention. It's you with a £2k diff that's #!+?

Why should you foot the bill for negligence.
Please keep the post running as i would like to hear the outcome of this.

Hope you get it on the road soon


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## -wizpip- (Sep 20, 2011)

Haven't had any word back from the people I've emailed regarding testing yet, but the TT Shop has removed the diff now. They believe the Haldex unit is undamaged and still full of its oil. The crack on the diff seems to go around the entire unit.

They've reiterated that they've been doing a lot of them for a long time, and this is the first cracked diff they've seen.

I've been quoted £3449.12 to fix it, with the part costing £3104.21. I found a website where the part new with VAT and delivery is £2,593.54, so I've asked how much it'd cost to fit that one. I've also signed up to breakeryard to see if there's any used ones going, and asked that if I could find a used one how much it'd cost to flush / refill / fit.

That first quote is 29% of the current value of the car [smiley=bigcry.gif]


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## John-H (Jul 13, 2005)

Your situation is a difficult one and you have been fair in your comments when many might have been quick to blame.

As you say, nobody has done anything out of malice. If a mistake has been made then that is an issue that needs to be resolved. I do wonder however how much of this issue is one of design - a contributory factor.

As I said before, the strength of the casting should cope with likely shock loads of 100% engagement, full torque and engine momentum, over uneven ground.

People are driving around Mk1 TT quattros with a bolt fitted, designed to give full engagement during travel and even during lift off engine braking. I've got a blue controller that engages on full throttle regardless of slip. There is an orange controller that adds lift off lock and other programmable controllers too. As with all Haldex systems the wobble plate pistons pump to give lock during differential speed difference when instructed. There is then unwind relief transitioning through zero differential speed difference.

If "instructed" 100% lock all of the time with a Mk1 controller (if driven hard) or bolt (continuously), why does that not wear out the diff but "instructing" 100% lock all the time with the wrong oil cause the casting to wear out and break on a Mk2? The obvious suggestion is that the Mk2 diff design is weaker.

So what contribution should the design authority bear if the wrong oil is added? I would suggest it depends to some extent on any warnings given but also on "fit for purpose". There is some approval for "official" uprated controllers I believe but I doubt the bolt. Perhaps Mk1 have been lucky with an over engineered Mk1 diff.

It may also be disappointing for some to learn of the limited potential for modification or performance stress if the Mk2 turns out to be weaker than the Mk1 in these respects.

Good luck with sorting it.


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## TT-driver (Sep 14, 2010)

-wizpip- said:


> Haven't had any word back from the people I've emailed regarding testing yet, but the TT Shop has removed the diff now. They believe the Haldex unit is undamaged and still full of its oil. The crack on the diff seems to go around the entire unit. [smiley=bigcry.gif]


That could mean the haldex end is still filled with old haldex oil. And that the rear end of the diff is filled with fresh haldex oil. (at least what still remains...)


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## -wizpip- (Sep 20, 2011)

TT-driver said:


> That could mean the haldex end is still filled with old haldex oil. And that the rear end of the diff is filled with fresh haldex oil. (at least what still remains...)


They've confirmed the Haldex oil is fresh and golden. The oil dripping out of the diff also looked pretty golden from what I remember.


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## -wizpip- (Sep 20, 2011)

Someone from Audi technical got back to me. I described what had happened missing out details such as garage names etc, and they instantly said it sounded like the oil was put into the diff. He also said that it would probably be difficult to prove.

A few places I've emailed for tests have replied with recommendations of other people to carry out the work, so that chain is ongoing.

Partial win for me though, my topic name was correct. This photo was labelled: The main bearing had collapsed.









Looks like the sort of thing that might, you know, make weird sounds in the wrong density of fluid...


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## TT-driver (Sep 14, 2010)

The look of that makes me almost as sad as listening to Leonard Cohen's very last song. [smiley=bigcry.gif]


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## John-H (Jul 13, 2005)

Well this makes more sense now.

Contrary to what that translated Audi FR document said about wind up on the transmission due to thick oil in the Haldex coupling, Haldex oil in the diff seems a much better way to destroy a diff - it's not a high pressure gear oil so will just wear out to the point that the gears get noisy and increase the forces in the casting when full torque is pushed through.

Worst still would be actually getting them the wrong round as that will cause a permanent Haldex clutch lock into a diff with inadequate lubrication. I can see that not lasting long - if you could imagine two mistakes getting made:- someone puts gear oil the Haldex at one service followed by Haldex oil the diff at the next to finish it off. Or the reverse order.

Well that explains that mystery then or at least highlights the danger :roll:


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## -wizpip- (Sep 20, 2011)

John-H said:


> Well that explains that mystery then or at least highlights the danger :roll:


If we were to say for a moment that it was Haldex oil in the diff, then that's a £3,500 mistake that I have to pay for. But, if a metallurgical analysis costs more than say £500 then it's likely something I'll have to stomach, because the risk of it coming back inconclusive, or simply structural failure of unknown cause, would be even more difficult for my credit card to bear!


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## TT-driver (Sep 14, 2010)

It doesn't take much oil to analyse with gas chromatography or mass spectrometry to determine what is what. In fact a couple of drops would be enough.

Question is: Will the garage accept the outcome of an independent analyst? And will they pay for the damage caused if it is due to their fault? If you don't have written agreement beforehand, any further investigation is indeed a waste of money.


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## C00P5TT5 (Jul 10, 2016)

Flashing lights and tooting horns it is then..... Daylight robbery wizpip!... What are you going to do? Second hand diff or get another ka?


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## -wizpip- (Sep 20, 2011)

P1723944 said:


> Flashing lights and tooting horns it is then..... Daylight robbery wizpip!... What are you going to do? Second hand diff or get another ka?


Found a brand new diff (it's the same one I have / had, which is isn't the most recent model) for $1,150 in the US. So, when they finish being busy with holidays, I'm going to try to convince them to sell it to me. Once it's shipped and has VAT slapped on it'll probably be ~£1,700, which is £900 cheaper than a new diff I've found anywhere else. I haven't found any old diffs. They won't reply till at least Monday, and their 9am is our 5pm.

That's the most important thing - getting the diff replaced, preferably as cheap as possible.

Then, I'm waiting for a reply from a company on the potential of doing a metallurgical analysis on the diff. So far, most of the people that have come back to me say it's definitely possible to confirm which oils are on the diff, and even why it broke. But they all only deal with the insurance industry. So I asked my insurer for help and they gave me details of people they know can help, but I won't get that reply till Monday...


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## GaryG (Aug 21, 2016)

-wizpip- said:


> Ha, even if something is wrong with the oil, they wouldn't have done it with malice.


If you are going to claim damages, i.e. the full cost or repair - and personally, I would do, it is unnecessary to show malice. Malice is only required when "special damages" are sought, and you have no evidence or even hint that malice is involved.

The legal point is that they are skilled tradesmen and they should ensure that the correct oil goes into the correct part. There is an expectation at law that they will do the correct thing - It is negligence if that did not happen - you require no other proof, and the proof is measured on the balance of probabilities, *not *"beyond all reasonable doubt, and negligence makes them liable to pay damages, *regardless *of whether they (i) knew or not or (ii) acted maliciously or not.


> And it's their prerogative to deny doing anything wrong until proven otherwise, because right now they'd genuinely not know.


May be, but this is not a wise course of action. They would be advised to find out by examining the remains of the oil.



-wizpip- said:


> But, if a metallurgical analysis costs more than say £500


Unless you are looking for original negligence in the manufacture of the part, "metallurgical analysis" seems to be a complete waste of money. You need the oil examining. All you need to show is that the wrong oil was put in a particular part.

As the sum involved is under £5,000, all this can be heard in the Small Claims Court.


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## -wizpip- (Sep 20, 2011)

GaryG said:


> May be, but this is not a wise course of action. They would be advised to find out by examining the remains of the oil.


I agree from reading other forums and speaking to other mechanics that if there's any question about the cause of failure and there's even the slightest possibility they they could be to blame, they should own the situation to minimise potential costs.

I guess at the moment I haven't pressed the issue enough, but as soon as I've found a third-party that can do an investigation, I'll go in and request one and present the people I've found as an option.

I'm sure it'll all work out in the end, regardless of any results


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## -wizpip- (Sep 20, 2011)

GaryG said:


> All you need to show is that the wrong oil was put in a particular part.


One of the scenarios is that the Haldex was changed properly, but in draining the chunk they also accidentally drained the diff. In this instance, there would be no oil contamination, but the metal would show fatigue / carbonisation as a result of heat.

But I'm still waiting for replies before I work out how to proceed. Weekends are so inconvenient!


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## -wizpip- (Sep 20, 2011)

Current update:

I bought the $1,250 diff (0BR 525 010B) from http://overlandpartsoutlet.com/products/differential-0br-525-010b?variant=24946792771 and paid $450 for delivery. With all fees and such it'll be about £1,750, which is £1,350 cheaper than a new 0BR 525 010G from Audi.

It's currently in Oakland, CA. Due with me next Tuesday!


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## WoRkZ (Sep 19, 2015)

-wizpip- said:


> [...] and paid $450 for delivery.


  WTF?! How heavy is that part that it would cost that much to ship anywhere in the world? It costs 500$ to ship A FULL CAR from California to here (by train though). You guys should have a train track built from here to the UK...


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## -wizpip- (Sep 20, 2011)

WoRkZ said:


> WTF?! How heavy is that part that it would cost that much to ship anywhere in the world?


Technically it's being flown rather than shipped, maybe that costs more!

The manifest says it weighs 100lb / 45kg - which is basically half of me.

It's currently on this aeroplane:
https://www.flightradar24.com/data/flights/fx36


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## -wizpip- (Sep 20, 2011)

Some images for you to peruse

Chambers of the final drive (diff on the left, Haldex on the right)









Shrapnel from my diff









Was the main bearing, you can see it's gone a bit wrong









Made a crack; here from the inside









All this stuff turns this nice gear arrangement









Driven by the Haldex chamber









From the Haldex unit


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## GaryG (Aug 21, 2016)

So the answer to "Did I bust a bearing?" is "Yes."


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## WoRkZ (Sep 19, 2015)

So when will you know if all this is coming out of your pocket or not? :?


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## -wizpip- (Sep 20, 2011)

WoRkZ said:


> So when will you know if all this is coming out of your pocket or not? :?


Well, that's the question.

Good news though, is that the new diff turned up and I've taken it to the garage!


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## Templar (Mar 9, 2012)

Anymore recent updates on this ?


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## -wizpip- (Sep 20, 2011)

Right, here's the finale.

Got the car back on Friday.

Labour (remove / replace diff): £468.00
Oils (inc labour): £109.99
Diff (new but old stock): £1,402.58 + £328.11 VAT / Import duty / Shipping

= £2,308.68

I saved £1,373.52 by buying a new (old stock) diff from America, over having a new (current stock) diff direct from Audi.

I have spoken to a few people about my car, one of them was Bedford Audi, where I spoke to the master tech. I told him the scenario backwards as not to bias him in any way. I said the diff cracked, and that previously I'd had a Haldex service and there was a subtle motorbike type noise coming from the rear afterwards. Without hesitation he started talking about how diffs can be accidentally drained, before I said anything about it, so he seemed to know and assume the score.

The independent person I spoke / sent photos to said that my description of the events (Haldex service, motorbike / whiny noise, diff crack) and the image of the disintegrated bearing all pointed to failure due to lubrication loss, which he said he would have attributed to the garage, had I not driven the car afterwards.

Let that be a lesson to you - if you hear a bang like you've hit something, but haven't, and can't see anything physically wrong with the car... get it recovered anyway. Don't try and hobble it off the motorway, realise that it actually seems ok, and start to wonder if you imagined it / did hit something.

So the independent guy and Bedford Audi both believe that the diff was drained, but neither can help me because I didn't have it recovered as it happened. I wasn't charged for this advice.

I outlined these points to the TT Shop, where Dave replied:



> With regards to the diff, we strongly disagree with the 'assessment of photographs' To give you an idea, in the 3 weeks around the date your car was serviced, we did a further 10 cars - that tells you how many we do and therefore our level of experience of these. No other car has had an issue, along with the 100's we've done in the past. We simply do not have an issue changing Haldex oil.


The only thing I can say in conclusion is... if you hear a whiny or motorbike pulling away type noise coming from the back of your car... check the level of oil in your diff.


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## BMTTS (Jan 29, 2016)

-wizpip- said:


> Right, here's the finale.
> 
> Got the car back on Friday.
> 
> ...


Was your diff the one with the apparent filter for life? I've just has my Haldex oil changed & I brought a Gen 4 filter for them to fit due to issues with this filter for life clogging (what happened in my last VW T5.1) Bloody expensive filter but good piece of mind.
My Haldex made a noise on first turn of being serviced but straight after that completely quiet.


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## TT-driver (Sep 14, 2010)

Glad that technically all is OK again.

I find the response of Dave to be poor. It would drive me up the wall, with or without oil.


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## -wizpip- (Sep 20, 2011)

BMTTS said:


> Was your diff the one with the apparent filter for life?


Mine is serviced as Haldex and filter, so I assume it's not a lifetime filter


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## -wizpip- (Sep 20, 2011)

TT-driver said:


> Glad that technically all is OK again.
> 
> I find the response of Dave to be poor. It would drive me up the wall, with or without oil.


I understand the denial, which is what I'd expect. The "We've done this before" defence isn't a good one legally though, because it can imply complacency. But it is what it is.


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## TT-driver (Sep 14, 2010)

-wizpip- said:


> ...it can imply complacency...


Which is very Audi like...


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## Gas TT (Feb 21, 2014)

Has an alternative scenario been offered as to what could have caused the failure from either Audi or another reputable technical source?

Will you be going any further with this ( i.e. Consulting any of the motor trades organisations) or are you just going to take the hit and move on?

Also would you use that garage again?


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## -wizpip- (Sep 20, 2011)

Gas TT said:


> Also would you use that garage again?


Just to answer this point; absolutely. Regardless of whether it was their fault or not, everyone makes mistakes. Even if it was their fault I think it's very unlikely it'll happen again, at least not with any great frequency. I've had a whole batch of Seagate hard disks fail before, but Seagate are still one of the top brands. The only thing that would put me off a brand / service provider is if they were continuously, demonstrably bad.

I fully understand their position as a business to deny any wrongdoing without another professional telling them otherwise.


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## C00P5TT5 (Jul 10, 2016)

What a humble, understanding, empathetic guy. My insurance premium would be a lot less with more people like you in the world wizpip.

That said, not to late to arrange a met in front of the garage with the horns blowing, the lights flashing and the engine's reving!


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## -wizpip- (Sep 20, 2011)

Gas TT said:


> Has an alternative scenario been offered as to what could have caused the failure from either Audi or another reputable technical source?


I'm not really sure it requires another explanation. Before the garage there was no noise, after the garage there was a motorbike like noise during acceleration in low gears. The 'main' bearing that destroyed itself is technically called a pinion bearing. Here's a nice dirty diagnosis resource: http://www.ebay.co.uk/gds/Diagnosing-Differential-and-Driveline-Noises-/10000000009118033/g.html

Of particular interest is my acceleration case:
*Noise: Howling while accelerating over a small speed range (gears previously quiet)
Cause: Worn gear set due to lack of lubrication or overloading*

Diff oil on a Mk2 is never changed over its life. The car had been driving without rear noises before the first trip to the garage. If the crack had somehow already been present, you'd have to have been blind not to have noticed it dripping when changing the Haldex oil as the Haldex unit is plugged directly into the diff. I assume it would have to have been dripping if it were cracked when it went in, as the noise was not there before but was after, so the fluid must have been lost whilst it was there.

I really can't see any other explanation for it. I'm quite a logical person (my job is in programming), and I'd really love another answer that makes sense. But I can't actually think of any other scenario that would completely fit the circumstances.

Anyone else?


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## WoRkZ (Sep 19, 2015)

-wizpip- said:


> Gas TT said:
> 
> 
> > Also would you use that garage again?
> ...


 :lol: You bring up pretty bad memories of flashing a pile HDD to get them back to life... :wink:

Really disappointing that you had to shell out all of this money yourself for something that is unlikely to be your fault... but glad to hear your car is finally fixed! Enjoy!


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