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What inspection port are you referring to that they found this leak? I had the my engine out and there are two internal shaft seals. The drive shaft goes directly through the transmission in front of the torque converter. But even if they were leaking inside the bellhousing area the oil could not get to the cat to cause a burning smell?? The only way I could see gear oil getting to the cat is if were spraying from the passeneger side output shaft from the transmission. In that case you should be able to see it on the outer housing no need for an inspection hole. Anyways you should have them point out the leak and snap a couple pics to post. If it is the output to the front left wheel it should be serviceable, but most likely you will need to drop the transmission.
Originally Posted by kastockton
Okay -- let's try this again.
A transfer case output shaft seal inside the tranny is leaking gear oil down through the inspection port onto the cat on the passenger side.
Audi has no material on repairing this issue. (i.e. replace trans)
Has anyone had this issue or any experience as it's a shame that the tranny is performing flawlessly, but for this leak.
As it stands right now I am left with two options... replace trans or have the gear oil topped every so often and deal with the smell.
You are right about oil. Front differential is separated from mid differential, but drive shaft tube is part of mid differential volume. It is not sealed on the marked end. On the other one it is.
I was not right. Found better image, almost shop drawing. Drive shaft tube is sealed on both ends, so it is dry. Or not if one of the seals is leaking.
It is also obvious that left drive shaft seal can be changed only from front differential side.
1. First, check Bentley and the TSB's. I vaguely remember reading something to this same effect--that the seal for the take off unit is not accessible externally and that a symptom is fluid is coming out a weep hole. Also, in this area of the tranny (the take off unit), I doubt there has been much of any change on that for several generations of trannies. Thus, you could look at the C5 and D2 and related archives as examples).
3. Try calling a ZF distributor for real experience and advice. A half dozen years ago these guys were few in number and kind of specialized aound the U.S. by car manufacturer (Audi, BMW, Jag, etc.), but now less so and more numerous.You need the Audi ones too, because (at least until recently) pretty much just Audi used the "A" variants of the trannies involved that signified AWD (as opposed to traditional RWD like BMW and Jag sedans). Eriksson in Connecticut was the one which in the "old" system seemed to lead on Audi's. I talked to them about my C5 4.2 and also had them rebuild my valve body. Peter Schmid (the name of the guy and the business) is the guy here by me in the Bay Area that seems to be the "go to" local source these days. See attached link for full list and contact info: http://www.zf.com/na/content/media/u...rs/PC_dist.pdf
4. If you confirm it is inaccessible w/out a tranny R&R--as in I bet you will be at least $2500+ just to deal w/ seal (OUCH!)--consider other practical fixes/compromises. One I have heard NOT to do is plug up the weep port with sealant; that can force the fluid out elsewhere or with other bad results (like blowing a seal between gear oil and tranny fluid elsewhere, which woud be a meltdown scenario). Instead, to eliminate smell but still have the leak, maybe you could fashion some kind of drip piece of sorts out of sheet metal and attach it somehow so the fluid doesn't hit the exhaust pipe on its way down. Or, look into gear seal sealants--in the "old days" I remember these existing oriented toward differentials and manual gear boxes. Since the part of the tranny you are dealing with is lubricated with gear oil to start with, maybe you can find a solution there. And worst case, its a fail and you have to take tranny out eventually anyway. I wouldn't be that casual with the internal ATF guts of the tranny, but the diff units are really just basic gear lubrication stuff. You could search on line, ask the ZF guys for practical ideas, and or get to an old line parts shop with career car guys who would know the available products--probably ones that either have solids in them that seal leaks, or ones that swell seals somewhat. A variant of the same stuff used to try to seal up leaking front and rear main (crank) motor seals.
If I exhausted my other options and tried to get a better idea from the ZF experts, the seal fix type additives in the end is what I would likely try myself as a "not much to lose" anyway choice.
Good advice. Through a friend the ZF guys (CT) were consulted and feel they have seen this before and would be able to fix at a fair price ($300) however the transmission would have to be sent to them. The R&R is somewhere in the 15-18 hour area and at that point why wouldn't I just buy a reman unit with a 2 year warranty, right?
The suggestion about a fluid the might swell the seal is, as you mentioned, worth a shot.
I appreciate all the info and diagrams... I am not a technician and must admit, some of it is confusing. Something tells me that with just about 90k miles this car is headed for a dealer for a trade in and then certainly bound for wholesale. I just don't know if I feel like investing the $3000 to $4500 needed to fix a leaking seal. It's time for control arm bushings, brakes and close on tires... you can see where I am likely headed.
I know the tech who diagnosed this "sometimes" reads this forum and I'll see if he's interested in reading this thread. Perhaps he wouldn't mind adding to this.
I am not a technician and must admit, some of it is confusing. Something tells me that with just about 90k miles this car is headed for a dealer for a trade in and then certainly bound for wholesale. I just don't know if I feel like investing the $3000 to $4500 needed to fix a leaking seal. It's time for control arm bushings, brakes and close on tires... you can see where I am likely headed.
I know the tech who diagnosed this "sometimes" reads this forum and I'll see if he's interested in reading this thread. Perhaps he wouldn't mind adding to this.
I think you are right. To drive this cars when they get out of warranty one have to be technically inclined and fairly handy to do things himself. If not it can get more expensive than lease for the a new car.
It would be nice if your guy chimes in. That would improve knowledge base so helpful when out of warranty.
P.S. If it is dripping from that drive shaft tube it won't hurt sealing that opening.
The seal is quite easy to replace once the transmission is out of the car.
it only cost $11.50 09E-409-400, it is also necessary to replace the flange bearing on the driver's side as the vibration from this bearing causes the leak.
but at 85k miles that transmission has barely any life left in it anyway so no point in spending all that money.
Either way most people don't realize that at around 90-100k miles the car needs so much more than regular maintenance.
everybody neglects things like brake hoses and brake hydraulics, shocks (people only change them when the air springs finally fail) but their life expectancy is only 70-80k, if they were to cost $20.00 they would get replace a lot sooner but because of the cost people never consider replacing them swearing they perform fine.
your idea of trading the car makes perfect sense.
I would not drive an A8 without warranty at all considering I can fix anything on it, just the time and aggravation/inconvenience is not worth it.
I drove an S class for 190k for a consulting purpose of long term reliability, and was very please to see the results.
my present S class has 100k but will be trade soon, considering it has perform flawlessly all this time.
for the first time we were considering the new A8 for replacement but has come the time that we no longer need a big 4 door car even though the one we are considering is the Panamera.
Hi,
I noticed a bit of oil in this location (to the left is the transmissions, to the right is the drive shaft.
I did not see the fluid trailing from the transmission, nor could i see it trailing form the top. The fluid did not smell like transmission fluid, but as you can see it was maybe gold in color (yes i have the gold Lifeguard ZF 6 in my transmission). So is what I am looking at the center differential (with the bar code sticker on it)?
Any idea what is leaking and from where... as in might i have the same issue the original poster of this thread had?
Also, is the the fill port for the expensive G 055145A2 center diff fluid sticking out the side on the bottom right of the picture.
Any advise would be appreciate, Thanks.
Last edited by Sci-fi_Wasabi; 10-16-2018 at 03:45 AM.
Hi,
I noticed a bit of oil in this location (to the left is the transmissions, to the right is the drive shaft.
I did not see the fluid trailing from the transmission, nor could i see it trailing form the top. The fluid did not smell like transmission fluid, but as you can see it was maybe gold in color (yes i have the gold Lifeguard ZF 6 in my transmission). So is what I am looking at the center differential (with the bar code sticker on it)?
Any idea what is leaking and from where... as in might i have the same issue the original poster of this thread had?
Also, is the the fill port for the expensive G 055145A2 center diff fluid sticking out the side on the bottom right of the picture.
Any advise would be appreciate, Thanks.
Yes, from the picture I think that is the center differential area, a.k.a. the Torsen differential.
Clean up the area as completely as you can with brake cleaner and some rags. Then drive and check again in a week or two. Hopefully the leak area can be narrowed down. I have never had to disassemble in that area. In old Audi's I typically just lived with differential leaks if it involved a seal that required the tranny to be pulled.
You can use the "cheaper" Audi diff fluid for the Torsen. The Torsen fluid has the magic "Sturaco" additive that makes it a lot pricier by the can. But it apparently stays behind on the parts so for top ups you just use the regular fluid like is speed for the front diff. See the ZF 6 speed tranny instructions (search...) if you want more comfort on that point.
No, the side protrusion is not the fill port for the center diff. The fill port is buried above the big aluminum cross member casting (and there is no drain port). I think just the beginnings of that cross member are in the far upper right of your picture. See reply 6 to my own thread here where you will see the fill port in the background above the cross member, and the mod I made to make it accessible. https://www.audiworld.com/forums/a8-.../#post24539687 You have to route the hand pump fill hose vertically up there and put a 90 degree plastic fitting on it to get the fluid in. Without that 90 degree fitting it will just come right back out in your face. There is something internal in the first inch or so above the fill port opening that blocks the hose from being pushed straight in and then off to one side like in a lot of oil jobs.
Hi,
I noticed a bit of oil in this location (to the left is the transmissions, to the right is the drive shaft.
I did not see the fluid trailing from the transmission, nor could i see it trailing form the top. The fluid did not smell like transmission fluid, but as you can see it was maybe gold in color (yes i have the gold Lifeguard ZF 6 in my transmission). So is what I am looking at the center differential (with the bar code sticker on it)?
Any idea what is leaking and from where... as in might i have the same issue the original poster of this thread had?
Also, is the the fill port for the expensive G 055145A2 center diff fluid sticking out the side on the bottom right of the picture.
Any advise would be appreciate, Thanks.
Yes, I think that is the center differential area in your picture, a.k.a. the Torsen differential.
Clean up the area with brake cleaner and some rags. Then drive and check again in a week or two. Hopefully the leak area can be narrowed down. I have never had to disassemble in that area, and in old Audi's typically just lived with differential leaks if it involved a seal that required the tranny to be pulled.
You can use the "cheaper" Audi diff fluid for the Torsen. The Torsen fluid has the magic "Sturaco" additive, but it apparently stays behind on the parts so for top ups you just use the regular fluid like is speed for the front diff.
No, the side protrusion is not the fill port for the center diff. The fill port is buried above the big aluminum cross member casting (and there is no drain port). See reply 6 to my own thread here where you will see the fill port in the background above the cross member, and the mod I made to make it accessible. https://www.audiworld.com/forums/a8-.../#post24539687 You have to route the hand pump fill hose vertically up there and put a 90 degree plastic fitting on it to get the fluid in. Without that 90 degree fitting it will just come right back out in your face, and there is something internal in the first inch or so above the fill port opening that blocks the hose from being pushed straight in and then off to one side like in a lot of oil jobs.
Thanks MP4.2, I was just hoping that maybe by the 2009 D3 they put the center differential fill port in an easier to access location... wishful thinking. I think the part I am focusing on (with the bar code label on it and the protrusion on the side, is something attached just further back from the differential you have pictured in you port fill mod. picture. Any idea what that protrusion is, it does have screw with an allen slot going into it, like the other fill ports? Well, I'll start by following your suggestion of cleaning up the area and monitoring.
Thanks
Last edited by Sci-fi_Wasabi; 10-16-2018 at 11:41 AM.
07-12-2011, 09:54 PM
