# DIY replacement of the rear silencer



## peter-ss (Sep 3, 2008)

My 1999 TT 225's original rear silencer was staring to get a bit tired and when I saw an as new one on the TT-Spares stand at Duxford I had to have it. £80 was handed over for the silencer that I later found out costs just over £384 from Audi so I was more than happy.









I set about replacing the silencer today and thought whilst I was at it I'd take some photos and produce a bit of a how to, so here it is.

HOW TO REPLACE THE REAR SILENCER

The original exhaust system on the TT is one unit (middle and rear silencer) but they can be replaced separately. The rear silencer that I'd got had about 70mm of pipe leading to it so I needed an exhaust coupling to connect it to my existing middle section. I spoke to Audi and found out that they do supply a coupling although there are different sizes. A quick measure of the replacement revealed that I needed a 60mm diameter coupler, which Audi had in stock. The part number of the coupling was 893 253 139 C and the price £23.07. It's a very substantial piece of kit looking rather like something you'd expect to see holding up some scaffolding.









With the new rear silencer and exhaust coupling to hand the first job was to put a hacksaw through the existing system after getting the rear end of the car on ramps. I measured how much pipe there was on the replacement and then marked the same position round the existing system after applying some masking tape (well I actually cut off about another 5mm to allow for adjustment. To assist with accurately marking round the pipe I found using a tape measure as a guide quite useful.









There was just enough room to manoeuvre the hacksaw and when nearly through I supported the silencer near to where I was cutting it. It's very heavy and I didn't want it to drop down, which would result in the tail pipes scratching the bumper.









Once through with the support holding the weight the next job was to partially release the exhaust from the two rubber mounts ready for removal. I found the best was to do this was to give the mounts a good spray with WD40 and then prise them half way off with an adjustable spanner.









With them both partially off I got an assistant to support the silencer by standing behind the car and holding it by the tail pipes. With the silencer still supported at the inlet side both rubber mounts were fully released and the system withdrawn with the assistant still holding it at the back. The cut end left on the car was then cleaned off with a file to remove the burrs. At this stage it was necessary to start the car to hear what it sounded like, ughm, I mean, blow any swarf out of the pipe.









The coupling was slid onto the pipe noting that the nuts face down and are on the nearside as shown in the manual that I was working from.









The rubber mounts were then given another spray with Wd40 as were the mounting pegs on the replacement silencer to aid fitting. With the help from the assistant again the replacement silencer was offered to the car, first locating the inlet pipe into the coupling and then hooking the two mounting pegs through the rubber mounts.









The manual states that the bolts should be tightened to 40NM but before tightening them up I rattled the silencer around a bit to make sure it had settled into position, ensuring no unnecessary stress on anything once the installation was complete. Also the coupling was centralised over the joint and the nuts positioned no lower than the bottom of the pipe. I was pleased to see that once tightened up the tail pipes were nicely aligned inside the bumper cut outs.









With the old silencer removed from the car it could be seen where exhaust fumes had been escaping from the corroded welds.









I was pleased with the end result, which cost me just over £100 and took about one and a half hours to complete.


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## maniax (May 20, 2010)

Nicly done. Good write up.

I think mine is blowing as well but i need to check that properly first.
martin.


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## T3RBO (Dec 9, 2003)

Good mod and nice write up... had my silencer removed nearly two years ago and was well worth the £70 I paid.


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## Charlie (Dec 15, 2006)

Another happy customer  glad it did the job Peter, it certainly looks nice and shiny 

Charlie


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## peter-ss (Sep 3, 2008)

Yes, it's great and wasn't too bad to fit either. 

Unfortunately whilst under there I found a bit of play in one of the rear track control arms so they look like being the next on the list. :roll:


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## Boyzy (Feb 25, 2017)

Nice one 
Have just heard my leaking and its the coupling rusted through thanks for the part number a easy fix thank god thought it was the back box at first


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## rodhotter (Dec 30, 2011)

wondering if i could use a single exit silencer on my 2001 225Q. i put a borla aftermarket cat-back on + could not get the dial outlets to match, always one in more than the other!!


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## Beardman123 (Mar 14, 2019)

Nicely done ! Ignore my naievity but what are the things called under your wheels holding it in the air after you've jacked it? Looking for something similar. Thanks


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## alexgreyhead (Oct 12, 2015)

Beardman123 said:


> Nicely done ! Ignore my naievity but what are the things called under your wheels holding it in the air after you've jacked it? Looking for something similar. Thanks


Ramps  I'd recommend getting plastic 3 tonnes ones - they're maybe £30 on eBay - as they're less prone to slipping and don't corrode or break over time.

I have these and would recommend them 

/Al


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## GARAGE HERMIT (Mar 7, 2015)

rodhotter said:


> wondering if i could use a single exit silencer on my 2001 225Q. i put a borla aftermarket cat-back on + could not get the dial outlets to match, always one in more than the other!!


yes you can, just cut the std back-box off then use a few 45 degree bend's, there you go,


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