gilee_8

Hey guys,
My previous post regarding Tranny leak, and Bob mentioned "I think you need all three output diff seals. The pass side and "prop shaft" seals are easy enough. The Driver side is a little more involved, the seal is pressed between the housing and flange." shown here <a href="https://forums.audiworld.com/a6/msgs/808449.phtml">https://forums.audiworld.com/a6/msgs/808449.phtml</a>
I just wondering where, what and how to replace the output diff seals? Do I have to remove the tranny?

The fluid that leaks out do drip to my garage floor (not alot) and it seems like clear fluid with slight yellowish or reddish to it. I cannot really tell.
And I don't believe it is engine oil because the bottom of the engine oil pan is very dry (compare to the tranny rear parts) <a href="http://www.rpi.edu/~leeg2/audi/tranny4.JPG"><img src="http://www.rpi.edu/~leeg2/audi/tranny14.JPG" /></a>

Any input will be great!
Thanks.

BernieBenz

The other half goes in the rear diff. + a full bottle in the engine oil, will stop all rotary shaft seal leaks for another 50K. DFI if IAB!

gilee_8

Will adding those "stop leak" thing mess up the lubricate? I never used them before.

I just read alot of information from the http://www.audipages.com/Tech_Articles/auto_transmission/Transmissionfluidcheckingrev1.pdf

So Are the leaks I am seeing from the pictures:
<a href="http://www.rpi.edu/~leeg2/audi/tranny1.JPG"><img src="http://www.rpi.edu/~leeg2/audi/tranny11.JPG"></a><a href="http://www.rpi.edu/~leeg2/audi/tranny2.JPG"><img src="http://www.rpi.edu/~leeg2/audi/tranny12.JPG"></a><a href="http://www.rpi.edu/~leeg2/audi/tranny3.JPG"><img src="http://www.rpi.edu/~leeg2/audi/tranny13.JPG"></a><a href="http://www.rpi.edu/~leeg2/audi/tranny4.JPG"><img src="http://www.rpi.edu/~leeg2/audi/tranny14.JPG"></a>

Are they the leaks from my Final Drive - Front and the Distributor gear or center differential?? Is this the prop shaft seal, tail shaft and pass shaft seal you guys mentioning about? or are they different things?

Thanks again.

A8CT

follow the procedure for the prop shaft (sometimes called tailshaft) replacement. It's where the back of the transmission connects to the driveshaft.

You can reference this procedure and the rear differential seal replacement to get an idea what's involved.

The 2 rear output, "prop shaft" and pass side/front output seals are all basically the same procedure. The Driver side front is the only one that varies a little because of the flange.

No, you don't need to drop the transmission. They're cheap and relatively easy to do. Once you get the axle/driveshaft out of the way you basically ubolt the center torx bit, swap the seal and re-assemble.

You'll need a seal puller tool. I would get a regular $10 one and invest in the kind you can use on a slide puller. These make it really easy to get the old seal out if you have room for it. I had a dent puller and just bought the new end for it and works great.

Bob

A8CT

when you do the filter/fluid change. Clean everything up and see if either the output shafts seals leak.

There's really no overlap in labor so that might be a good start.

gilee_8

From the pics, and from my memory of looking up from the bottom of my car. (from the info I obtained from you guys) it looks like the passenger prop shaft seal (the one that connect to the passenger axle) is leaking:
<a href="http://www.rpi.edu/~leeg2/audi/tranny1.JPG"><img src="http://www.rpi.edu/~leeg2/audi/tranny11.JPG"></a>

And in the next picture, the tailshaft seal is leaking:
<a href="http://www.rpi.edu/~leeg2/audi/tranny4.JPG"><img src="http://www.rpi.edu/~leeg2/audi/tranny14.JPG"></a>

Does both of the above look like leaking to you guys? Do you guys see or think other things are leaking too? or just that two area?
The rear diff looks completely dry, no oil in sight anywhere. So the only oil I see when I get below my car is the two pictures above. I just want to make sure my driver prop shaft seal is ok (since you guys said that is hard to change) And said that the tailshaft and passenger prop shaft seals are easy to change. (Man, and I just changed the entire pass axle for 2 weeks ago too...)

Two more things:
1) the tailshaft seal look like it is leaking very badly (just the way it looks) it is not just wet but looks like dripping off! Do have to do the seal fix immediately without driving? do I have to fill up the gear oil asap first? is it easy to fill up the gear oil or I better off just change the seal.
2) all the fluid the car is leaking are gear oil? I mean both the tailshaft and pass prop shaft seal. Or is the passenger prop shaft is leaking ATF?? I am confused because from the online diagram of the Tranny, it looks like the front is using ATF and the rear part uses gear oil. Or do they both share the same source of oil storage?

Thanks again.

A8CT

there are 2 differential fill plugs on that transmission:

1) the front ("front final drive") is on the pass side pretty much straight through when you take the wheel off. Look for an (8mm?) hex plug. Unscrew and top it off until the fluid dribbles out. This will top off the reservoir for the pass and driver side output seals.

2) Yes, your prop shaft seal has a pretty good leak. I would fix that one first, then maybe do the pass side output seal next.

The issue on the A6 is that the fill plug is sandwiched right near the exhaust but you probably need to drop it anyway (like the A8) to get enough room to change the seal.

It's might be possible, but I don't think you can get the fill plug out with the exhaust in place. So, you can top off the front but the location of the plug in the rear ("rear final drive") might force your hand to just drop the exhaust and fix it.

There is a drain in the rear (same size plug on the bottom). There isn't one for the front.
BTW, the "rear final drive" is a totally seperate unit which you probably guessed because it has seperate fill plugs. This is where the fluid is coming from that's leaking out of the "prop shaft/tailshaft"(same thing).

Any/all that are leaking will be gear oil. There won't be any trans fluid leaking around the flanges. The only trans fluid leaks will be around the pan and/or the big fill plug. That takes a rubber o-ring and the "kits" usually don't come with a new one.


Bob

gilee_8

Thanks for the details!
My kit comes with 2 new O-ring and the gasket, so hopefully that will fix the problem.
I will have to order the seals for the passenger and tailshaft seal.
Any idea on where is the cheapest? will dealer cost around the same on these seals?
Thanks again!

A8CT

yeah, go with dealer/OEM. They're not too bad, $20 a piece.

gilee_8

Thanks again.