Giovanni Giovino 6.0+6.0TT

Hello Louis,
I had the O-rings / flat rubber washers leaking on my W12, it started like this, while I was at a trans service shop having my son's A6 4.2 trans rebuilt I asked Pat the owner to throw my A8L on the lift to check the level and look for any leaks, well we all looked and his tech said "it is the pan", but to me the oil stain was to far forward, and as it was late in the day they could do nothing but snug up the bolts which really did not turn much, my trans had just started to act weird like cubchief3 describes, 3rd & 4th when cold, and sometimes a little slow going from park to reverse, nothing major, just enough to make you think, well long story not so short I drove the vehicle the 70+ miles home from the trans shop and went to Audi in the morning to pick up many liters of tranny fluid along with a filter and pan gasket, that night at a friend's shop whom let's me use the lift after hours, I was pulling the exhaust to drop the pan and said to myself, "let me clean all of this to spot the leak" so I sprayed the whole area with brake clean and took her for a short ride, I came back to find the trans cooler's seals leaking, not the pan, it was bone dry, so as these were a rubber flat washer type like an old faucet washer and I had none, I cleaned them with a solvent and flipped them over into their receiver spot, I then brought the trans temp to proper temp reading with VCDS, removed the filler/check level plug on the bottom of the pan and inserted my tube with slight "J" bend and added fluid until it ran out the same filler/check level plug hole as the tube was inserted, it only took about 3/4 of a liter, that was 40,000 miles ago giver or take, and the seals have held up and the trans has shifted like it should ever since, so yes, a minor low level can and will cause problems.

TSHong

+2. When I got my 05 W12, it had a lazy shift in the lower gears. Topped of with about 3 liters of Blue Audi ATF. I saw a TSB on loose pan bolts and sure enough, three of the bolts were not even finger tight.

ltooz_a6_a8_q7

So nice to hear all real success stories, so the key word I seem to notice is 'top' and 'fill up'. I think the answer is check for leaks and need to know how much oil we need to top it up with. You definitely don't want to over fill. Do we have the procedure on how to NOT over fill the tranny? So, 3-4 is the sign of low fluid. When my time comes, check for leaks and loosened bolts.
Thanks guys,
Louis

Giovanni Giovino 6.0+6.0TT

Yes, we use VCDS to monitor the trans fluid temp, and when at the correct temp you fill until it pours out, if the trans is to cold you will end up with a overfill, if too hot it will be under filled, I have heard of some using a heat sense gun pointed at the pan to read the temp, but never did that myself.

dvs_dave

MP4.2+6.0

Yep, FWIW I cross checked VCDS reading against a (quality) Fluke IR heat gun, both set to centigrade. Basically, always identical at the ½ degree C/1 degree F level. After that confirmation, I just used heat gun aimed at pan area so I could do it all at same time under vehicle w/ no keystrokes and such. Still use the VCDS at end of the service to trigger an trans. adaptation cycle at beginning of the prescribed driving loop.

I have also fully fixed my W12 with shifting issues at approx 100K with a solenoid and valve body seal change. Approx $5-600 in parts, plus the fluid. Like 10% of a rebuild and R&R and end result was shifting like new--as one who remembers from when I bought it at low miles as a one year old CPO. But yes, it may take more than a fluid change. Comprehensive fluid change is either 2 or 3 fluid cycles anyway (with a pan drop and filter change among one of them), so not a waste to try first one. Much more so since as several of us with experience have noted, the issue may just be a fluid loss that then needs topping up. From both C5 4.2 and D3 experience by a couple of quarts down (out of 10), shifting acts up. Happens variously due to pan gasket leaks, cooling lines and so on.

ltooz_a6_a8_q7

I forgot to ask you GG, which version of can bus controller did you get that supports both camera and ACC?

ltooz_a6_a8_q7

Now, the million dollar question, how do you warm up the tranny stationary?
Cheers,
Louis

MP4.2+6.0

Well, I guess that would be what most any service manual--or first person experience with it--would say. You start motor and wait, with vehicle level. Vehicle level means either a lift in turn or some combo of jack stands, ramp or driveway slope. Simple as that.

Back up to a bigger picture understanding of tranny. The tranny has a motor coolant to tranny fluid heat exchanger so is receiving heat that way. By definition torque converter is always spinning too since it is bolted to engine flywheel, and thus tranny oil pump is running any time motor is too. You simply pump tranny fluid in cold (if drained), then close fill port. Then start and re open and pump in more--a couple of quarts difference as soon as you start it. Likewise why you never open it with motor off unless you intend to drain it--and another way through unschooled maintenance fluid level can get screwed up. Then bring temp up to the 40-45C spec, let extra run off or top up as needed, and close it up. You can save a quart or so if you don't top it up until it hits the target temp, but I prefer to overflow it to essentially flush a bit more of the remaining old fluid out through dilution.

All well understood in ZF tranny service for last couple of generations--which are most Euro auto transmissions save Mercs, and have also been found in occasional Fords, Hyundai's, Nissans and other vehicles farther afield. On the other hand, if the mechanic only knows a Honda, Toyota or GM slushbox or whatever, not likely to be on top of it.

ltooz_a6_a8_q7

Thanks MP4, we can use the level against the frame to make sure it's on the level, I guess