definitive info on leaking rear output shaft seal

[andycaca]

hello everyone, guess what's leaking on my car again?
thats right, the rear output shaft seal - dripping onto the passenger side cat and giving off a nasty burning smell.


i've had a look through the service history and it has already been replaced at least 3 times:

67k miles, 2006
86k miles, 2009
112k miles, 2013

each time, it has just had the seal replaced. as we all know by now, the original seal is not up to the job and audi modified the flange and seal.

here is where my knowledge breaks down, and i am unsure of the exact parts needed to fit the new seal and flange?

i'm currently installing ETKA to look up part numbers and try to figure it out myself. in the meantime, if anyone has done this and replaced with updated parts, the part numbers and exact parts required would be very helpful.



additional reading:
http://www.audipages.com/Tech_Articl...placement.html <- DIY to replace JUST the seal

http://forums.quattroworld.com/a8/msgs/32544.phtml <- replacing with updated and modified flange, seal etc

part numbers identified so far (according to the internet, not verified)
01V-409-809-A <- new flange/shaft (ZF part number 1058-336-122)
01V-409-524-B <- new cover with seal (ZF part number 1060-236-063)
01V-409-399-A <- just the new modified seal
018-409-399-B <- just the original flawed seal

from my research, the modified seal will not fit correctly into the original cover


*this post is incomplete but i am posting it because i need to reboot my pc now!

[Adrian E]

Mine came from the factory with the modified seal - to my knowledge it's been done twice and it hasn't completely stopped the leak

I did buy a replacement tail shaft but there was nothing wrong with it and it doesn't interact with the seal so can't be to blame for the ongoing leak.

I think the stupidly precise measurement of how far in it should be is probably the route cause. Easy enough to achieve with the box out of the car, but near enough impossible with it in!

There's recent threads on this where part numbers are posted - there's even a flange advertised for sale on here that's BNIB (not mine)

I would strongly recommend checking the flange before buying a replacement. No point buying it if it's on the car already!

The 'old style' seal is part number 018 409 399b
The one for the modified tail shaft is 01v 409 399a

The modified flange is 01v 409 809a and RRP is about £190

[andycaca]

thanks adrian, thats good stuff to know.
as im having a local independent do this (alongside cambelt replace) I will ask them to check the flange type fitted. i have no reason to believe its anything other than the original one tho.

using ETKA, is there any way to type in a part number and then have it bring up the parts diagram where it is used?

[Adrian E]

Yep, go into the '8 section and select the year, then click on the binocular symbol at the top and pick one of the tab options. Think there's 2 tabs that'll take the part number, but the heading where you can choose this model/all models/all brands is I think the one you want

The flange turns up in 2 sections, from memory

[steamship]

Originally Posted by Adrian E

Yep, go into the '8 section and select the year, then click on the binocular symbol at the top and pick one of the tab options. Think there's 2 tabs that'll take the part number, but the heading where you can choose this model/all models/all brands is I think the one you want

Thanks for that. I tried doing that before and never even noticed the various tabs in the search window. Something learned every day.

[andycaca]

quick question: does the actual shaft need changing if i were to replace the cover & seal?

it would be nice if it doesnt. unfortunately i have read conflicting/vague stories on the internet.

when my car goes in for the cambelt i want this job done at the same time and with the minimum or delay

[steamship]

Originally Posted by andycaca

quick question: does the actual shaft need changing if i were to replace the cover & seal?

On my '01 3.7, it was one of the first jobs to be done. The person I bought it off had already bought the seal, but had never got around to fitting it. Shaft didn't need changing.

[andycaca]

update on this. after having the seal leaking ever since i bought the car i finally got around to replacing it.

well, i actually paid a friendly mechanic to do the job, as he had a handy lift to put the car on. this job is definitely doable on axle stands if you can get the car high enough but for £30 i wasnt going to roll around on the floor for an hour or two.

couple of points:

1. the left hand cat must be removed. you can remove the cat "insitu" without removing any other bits of the exhaust system. the cat to mid section joiner is one of those cool sleeves. undo the bolts and tap the sleeve towards the cat (you cant go the other way because the exhaust has a bulge in it)

2. remove the ally prop brace to give you a little room to wiggle the prop

3. press the replacement seal in very carefully. ELSA says to press the seal in 1.7mm past flush. we got to 1.63mm and left it there.

no photos as i was too busy tidying up the rear bumper and fitting new number plates

hopefully you can see this picture

[Adrian E]

Looking good

I really like the little lip spoiler on your car - might have to look at getting one for mine when I get around to getting a few little paint jobs sorted

Interestingly I've not been smelling diff oil from mine for a while - my initial impression that the 2nd seal hadn't worked to cure the fault might've been premature. Given how much had leaked out and how widely if gets spread it may just've been residue taking time to burn off

[HPsauce]

Originally Posted by Adrian E

Interestingly I've not been smelling diff oil from mine for a while

Nor me strangely, the most recent seal replacement has clearly cured the final leak.

Somehow I miss it as the aroma has been a regular feature of both my B's over the years from one output shaft or another.