tester123

Tired of the constant leak and decided to replace the tailshaft seal. Well, this is turning out be a bigger project than I had anticipated. First, the innocent looking heat shield torx screws stripped. So, that's not coming off. Next, I thought to remove the shaft itself from both the transfer case and the rear differential. All the bolts are out but the rear-diff wouldn't slide out and few time of hammering/pulling doesn't seem to do much either. I also loosened/removed the shaft bearing (middle) mount to give it more play but that damn shaft is not out yet !

Next I have two options that come to mind. One, drill out/tap out the heat shield screws and replace them once they are out. Two, keep trying to hammer/pry out the shaft at the rear differential; still, that would make it difficult to replace the seal and in-general do a clean job.
Any ideas here?

Lastly, the center bearing support bracket. Does that need any special alignment? Elsawin and Bentley suggest a tool to shimmy this and that etc., using a special tool to hold the shaft in place. I don't have access to such tool so, what is the best way to ensure it is installed properly (other than doing my best to position it back using existing marks on washer/bracket)?

tester123

Update: Ended up drilling (alternating with Brake cleaner and PBlaster), hammering in a torx bit and 3/8 ratchet to loosen it. Thank GOD they came out and I was able to complete the seal repair. But Shame on AUDI engineer(s) for putting a soft bolt with a Torx head. To me, it screams "Service Revenue". Replaced them with excellent Hex head bolts from a local store. Don't tell me AUDI cannot put simple head bolts.. heck they have same thread as the cv/shaft bolts!

Airbag

i neeed to do mine again .. tired of the awefull smell of that fluid dripping on to the cat. i left my drive shaft in place last time , just dropped the support and it moved out of the way enough ..


what dd you use for a seal and fluid ?

N_Jay

How do you replace an output seal without removing the shaft?

I need to do this on mine. I am hoping it is not so tough a job. (2.8 Quattro)

For now I am just going to top up the central diff fluid and wait for spring. (Car will not be home till then)

Airbag

i left the back end in place and did not remove the whole thing. i just undid the bolts at the universal ( cv) joint and at the the support bearing .. then it dropped enough that i could just move it out of the way .. the flex joints in the exhaust should move too but be carefull here . if they are old they will tear and now its a PITA s you have to repair flex joints too.

There is a newer style tail flange that is suppose to be better for leaking but i think im just going to try and throw another seal in .
Do you guys get the smell to as it drips ?

audipages A8 Transmission Seal Replacement

tester123

Bought the seal from a local Audi/Euro parts dealer around $15. The fluid if I remember correctly is 75w-90 gear oil (Ravenol -Blauparts). Works fine.

tester123

Yes, of course we get the smell when the oil drips on to cats.

I understand what you are saying here but without removing the heat shield, the shaft does NOT drop; can be loosened of course. Releasing the center bearing support doesn't help either that's why I was trying to remove the entire shaft.

tester123

Without removing the shaft??? Umm, not possible. The flange (think of the splines end of a CV shaft) is inside the transfer case part of transmission. The shaft is then bolted on to this. But the splines end "flange" is held in place with a "40" torx (IIRC). So, the procedure is (on 4.2 anyway):

Remove exhaust, remove heat shields, remove the "heat shield" below the shaft (Major PIA in my case, again 40 torx, I believe) and then proceed to remove shaft bolts. Remove the center Torx bolt holding the flange and the flange comes out. Pry out the seal. (you may have to loosen the center bearing support for more room/access). push new seal in and put it all back the way it was.

Is it tough job? NO. With a lift and good tools, it should be an easy job. (stripped bolt heads -my story). Plus, I had the front on ramps and rear on jack stands. So, crawling in out was PIA, not to mention little room to use tools. Otherwise, it is a good project. Just make sure to secure the center bearing bracket in exactly the same place (old washer/nut marks). Also, don't loose the space washers or "shimmys" and don't swap them.

tester123

Finally, I feel better. The long waited maintenance is done.

Completed the drive shaft seal repair and changed gear oil.

Changed the Front differential gear oil - came out almost black. 1 liter of new oil. Runs smooth!

All rotors and pads with full brake fluid flush. Stops like it is supposed to now.


The front differential filler/drain bolt is in a very tight spot. Used a allen bit with a wrench and a pry bar! Yeah, why didn't I think of this last year? Duh!
Anyway, this one is odd because you have to pump out the old and pump in the new fluid. simple enough.

Airbag

yup. your description is how i did mine my screws for heat sbield just broke off tho

a definite pain on stands my dealer wanted 40 bucks the the vitron seal crazy