1992S4

I recently discovered that my manual transmission is leaking gear oil at the back near the driveshaft.
What could it be? Is this a DIY or..?

Willem

EricAl

I just experienced the same leak on my treasured 95 S6. It is a diy IF you have access to a lift. It necessary to remove the exhaust and cross plates to get access to the transmission. Once those items are removed, the rest remains easy.

The task involves removing the tail section of the transmission, removing a retainer and pressing the tail shaft assembly out of the bearing. Most of the work is done on the bench.

I chose not to do it myself since I do not have access to a lift and had it done by a foreign car tech whom I have known for about 20 years.

He first attempt was not successful and he did the job over and I am still not SURE it is not leaking.

The task involves replacing the tail shaft seal plus an O-ring that seals the tail shaft housing to the transmission.

I would suggest replacing the output shaft bearing since you will have everything apart. And change the trans lubricant. Make sure the transmission vent is clear. I understand some leaks had been traced to a clogged vent causing pressure to build up in the trans forcing lube past the tail shaft seal.


The parts from Audi are expensive - get them from one of the import parts supplier.

Good luck,

Eric. 95 S6, 18 inch Avus, Big reds, Eibach, chip, digital boost ga.

1992S4

Thanks for your update Eric. I've read your thread and this completes it. Where is the vent located? Can you see and clean it?
I'm a guy that needs some reference material before starting a job, so a manual would help a lot. I saw on erwin.audi.com that they changed prices for their manuals to flatrate pricing, too bad.
What did it cost you to have it done?

Willem

EricAl

I expect you discovered the leak as the result of the smell. Trans fluid on the cats is quite noticeable. I still have some smell but it may be residual fluid still burning off.

<<<Where is the vent located? Can you see and clean it?

The vent is located on the top right front corner of the transaxle roughly above the right inner u joint and below the steering rack. To see it, rest your chin on the air cleaner plastic cover and sight above the exhaust flange aft of the exhaust bellows and you are looking at it. There is a plate on top of the transmission and the vent extends thru the plate. It is about an inch and a quarter tall, almost and inch in diameter and has a loose but captive plastic cap. You can reach it from the top with your left hand.

I paid 375 labor; 56.40 trans fluid; 28.78 for the O-ring; 12.51 for the seal, about 66.00 for the bearing so about $510 total. As I said, check the import parts houses for better prices.

I have Bentley and provided it to the tech for which he was grateful.

Let us know how you do.

Eric.

1992S4

I'll check the vent and clean the oil at the back, but I don't think that in my case the vent is the problem. If I park the car level, it leaks less oil when the back of car if faced down slope. I checked an Audi specialist (no dealer)for this problem and it seems to be a common problem. I'll ask for a quote (due to Carnaval in The Netherlands) end of week to determine if I'll do it myself.
Is it possible for you to make a copy of this specific job out of your Bentley?

Thanks for your feedback Eric, much appreciated.

Willem

Turbo_Anarchy

So Eric, was your vent plugged? You never posted about it.

SkiS4

I just did this job myself about a month ago. It does take a lift and about a full day IF you a press to r/r the shaft/bearing from the trans end cover. Parts were about $35 for both bearing and seal from the dealer.

1992S4

Can the job be done by putting the car on stands and lying on your back. Do I need special tools to replace the bearing and seal?

Willem

SkiS4

I guess it could be done just on stands. probably going to make it a bit harder to remove the exhaust and driveshaft.