When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Sorry about that. It is a hex plug on the transfer case. I remember it being on the passenger side. The transfer case is right behind the transmission. IIRC it's not super easy to get out the first time. I recall getting an allen wrench in it and either putting a cheater pipe on it or hitting it with a hammer to break it loose. I was looking for a picture but couldn't find one.
I have the s6. Can't even see the plug... exhaust in the way and transfer case holder wraps all along the bottom of the case. Anybody else have this issue?
Is it logical to just do the transmission oil changes and transfer case oil changes every 50K miles? I mean, doesn't gear oil for differentials last > 200,000 miles?
Also, let's get real. Audi's transfer case cannot be that strange compared to the transfer case oil they sell at advanced auto parts for $16:
Can I just use it?
Here's the diagram of the transfer case:
Uhhh, where is this, exactly? Underside but rear of the transmission?
Given that there is only one plug, is it correct that you need a curved tube to remove the oil and putting it back in will be on the messy side of jobs?
Is it logical to just do the transmission oil changes and transfer case oil changes every 50K miles? I mean, doesn't gear oil for differentials last > 200,000 miles?
Also, let's get real. Audi's transfer case cannot be that strange compared to the transfer case oil they sell at advanced auto parts for $16:
Can I just use it?
Here's the diagram of the transfer case:
Uhhh, where is this, exactly? Underside but rear of the transmission?
Given that there is only one plug, is it correct that you need a curved tube to remove the oil and putting it back in will be on the messy side of jobs?
transmission filter transfer case differential front. (no image of the rear)
ZF sells the fluids, gaskets, complete overhaul kits, etc. Note that they list two fluids (not one) for some components/situations.
2008 S6, to whom it may help. Center transfer case does have drain plug drivers side ( very difficult to get a hex in ) also has fill plug passenger side top. Both are blocked by the transmission crossmember. Driver side, transmission end low, above transmission crossmember. Fill plug, passenger side, driveshaft end high, above teansmission crossmember.
Amazing how many different transmissions out there. My front diff oil was fine and I regret changing it. The xfer case oil was a little dirty. I decided to not to even do the rear diff given how clean the front diff oil was. I replaced all the o-rings on those fill nuts though. You can purchase a used diff if one of them goes bad on the cheap. The xfer case however I am not sure if that's a whole tranny swap or not. I was going to post my own walkthrough but just don't bother is an easier solution.
Amazing how many different transmissions out there. My front diff oil was fine and I regret changing it. The xfer case oil was a little dirty. I decided to not to even do the rear diff given how clean the front diff oil was. I replaced all the o-rings on those fill nuts though. You can purchase a used diff if one of them goes bad on the cheap. The xfer case however I am not sure if that's a whole tranny swap or not. I was going to post my own walkthrough but just don't bother is an easier solution.
I just bought this car few weeks ago, above average condition for 105k miles. Southern car i will be driving 2400 miles back to New England so I was looking it over as I do with any audi after I buy. First noticed oil sweating through the oil pan because it has no ****ing gasket on it... classic. Also noticed front differential fluid seeping through the very bottom of the casing where at the mounting bolts, after it warms up you can see it actually fissing through and bubbling only when fluid is hot. Eventually I have come to the conclusion that the gear oil is actually overheating even when car is just idling sitting still. So either the fluid in it is wrong or it is original fluid that is just done. Ironically the car has the ports for a differential cooler but for some reason put just a bypass pipe on this model which is bizarre, easy enough though to just add it. Also so many people saying you need to suck front gear oil out because no drain port... just take the cooler off if you have it or the bypass pipe and drain it from there. I wouldn't have bothered with the transfer case other than the fact it shares fluid with front differential so obviously if the fluid is overheating I am going to drain both and refill. I have chosen Amsoil Severe Gear, Ams oil also has a 4 ounce tube of friction modifier for $11 bucks. I just bought an icon impact rated triple square low profile set (new harbor freight item hadn't even been put on the shelves yet...bought time HF!) So that I can loosen and lower the transmission mount bracket which is what blocks you from getting a hex into the drain plug. This can all be achieved so far without removing exhaust. I did loosen the center hanger mount bolts so exhaust would lower right to the crossmember right there. The biggest issue is the transmission cross member it can be lowered but not moved front to back. To be able to remove it the easiest way seems to be disconnect the exhaust at the front driveshaft point, remove the center and rear hangers, potentially the little crossmember and you should be able to remove the entire exhaust or slide it back. You would then need to disassemble the the goofy little shock absorbing hanger right there because the bracket goes up and hangs from the top. Once that is gone you should be able to wiggle the crossmember or slide it back to gain full access to the drain plug which would still require loosening and lowering the trans mount on the bottom. Trying to avoid all that for now. I wasn't able to get an 1/8 inch rubber hose in to the fill port to suck fluid out, it immediately hits a gear which is why I am back to removing the drain plug. Drain plug is right above. You may be able to get a very low profile hex bit on it with mount attached about 1 to 1 1/4 inch of clearance.
"Drain plug is right above. You may be able to get a very low profile hex bit on it with mount attached about 1 to 1 1/4 inch of clearan"
I tried so many dumb andidiotic ideas ranging from a pair of closed 5/16" wrenches (just one couldn't handle the torque) over the 8mm hex to dremelling down the bit height to the bare minimum and getting what's called a wrench extender, a very handy $10 tool you of course cannot purchase in any brick and mortar store. Not helping was the lack of any affordable 1/2" 8mm stubby hex bits. So, I needed to use a 3/8" drive and connect it to the wrench extender. All under the car. Perfect job for owning a lift. This job was a bit of a wake up call to me as it should have been quick. Obviously if I had to do it again it would take 10% of the time, but massive lesson learned about being prepared. Especially the need of a strong electric pump. I tried a few cheap pumps, like a $2 fish tank pump for air. No go. Very nice pictures there.
But which oils were actually dirty on your car?
"Drain plug is right above. You may be able to get a very low profile hex bit on it with mount attached about 1 to 1 1/4 inch of clearan"
I tried so many dumb andidiotic ideas ranging from a pair of closed 5/16" wrenches (just one couldn't handle the torque) over the 8mm hex to dremelling down the bit height to the bare minimum and getting what's called a wrench extender, a very handy $10 tool you of course cannot purchase in any brick and mortar store. Not helping was the lack of any affordable 1/2" 8mm stubby hex bits. So, I needed to use a 3/8" drive and connect it to the wrench extender. All under the car. Perfect job for owning a lift. This job was a bit of a wake up call to me as it should have been quick. Obviously if I had to do it again it would take 10% of the time, but massive lesson learned about being prepared. Especially the need of a strong electric pump. I tried a few cheap pumps, like a $2 fish tank pump for air. No go. Very nice pictures there.
But which oils were actually dirty on your car?
It isn't necessarily the gear oil being dirty, it's that it is overheating for whatever reason and leaking through the machine flat mating surface. Gear oil is fairly thick and should not leak through which after testing it was exactly what was happening, after a good 15 minutes of car running even not moving, oil starts coming through after it gets warm and fissing thriugh and bubbling like its pressurized. It gets so hot that it concerns me. Gear oil should never get as hot as this is getting so it is either original fluid that has been abused so much it has no properties to stop friction, or a previous owner changed it out with an incompatible fluid (included pic). Smells like Gear oil and does seem dirty, could potentially be atf fluid. As I am about to drive this car 2400 miles I can't have it boiling and running dry in the front differential. I even torqued the lower mounting bolts a little more and it still comes through. You would use this same method for replacing the transmission rubber mount and to drop the transmission pan.
From front differential. Seem on bottom of differential it was leaking through, origonally thought it was over filled and was coming out the breather hole. You do need to remove the rear crossmember this sits on so that you can lower and slide it back. The exhaust on this car is goofy, 2 pairs of catalytic coverters, 1 pair of resonators, 1 pair of mid mufflers?, 1 pair of mufflers, 2 pairs of flex pipe. Originally thought it had vacuum actuated valves in the rear like the rs4 does as it sounds different in sport mode, but i beleive it has them high up on the down pipes somewhere by the manifold to bypass one sets of cats and into the others. You can easily remove the passenger side exhuast piece, on drivers side with a bunch of pivot extentions you can just loosen the flange bolts as they are alot higher up on the down pipes for whatever reason. I could remove the crossmember but i have no need, it is far enough back that i have full access to the drain plug.
07-22-2016, 12:59 PM
