I am having problems with my 1999 A8 and any help would be greatly appreciated. I am the 2nd owner having purchased this car coming off a 3 year lease. When first getting this car I noticed an annoying problem that I thought was just characteristic of the car, now it has gotten much worse. When traveling between 35-40 mph, if I encounter a slight uphill grade the transmission would downshift then upshift and continue bobbing between gears( I suspect 2nd and 3rd) until I accelerate past 40 mph. I just watch my tach bob as it goes back and forth between gears. This is especially annoying seeing as much city driving is done in this speed range. I had the Audi dealership do a complete flush and filter at 70,000 miles. It made no improvement. Now I just turned 100,000 miles and the problem has gotten much worse. Now the slightest grade and even level highway gets the transmission floating back and forth between gears when I'm steady at that 40 mph. I just took the car to the Audi dealership and guess what, they say I need a new transmission. No technical explanation-no options-nothing. I ask them about reprograming the shift points and they said it can't be done. I really wish the Audi dealership knew more about their cars. Oh yes, I've even called AOA for technical assistance and they knew even leess, said the dealership has the information.

 

I just changed my tranny and sometimes still have this problem.It is definitely control problem. It can be TCU or maybe toddle position sensor. At that speed you hardly touching the pedal. The TPS moves very little. It's like a radio volume ****, after a while it wears out. I just keep it in third gear at that speed and no problem.

 

Does it behave in Tiptronic mode? If so, I'd use that from now on.

 

If the ECU sends all shift signals to the transmission and torque converter lock up signals, would not a new ECU be better or more up to date. Has anyone just replaced one just to see? I can drive down the road and watch the ECU send signals to lock /unlock/pause. Shouldn't we suspect the ECU?

 

My 98 A8 had exact same problem. I took it to dealer at 80k and the mechanic noted on my bill "the transmission seems to be searching for a gear". The service advisor told me "not to worry, it was just a nuisance" so I dealt with it for 22k (1yr). Forthermore, was not told anything about changing fluid- I assumed they would say something if it were important. Here I am now with a car in limp mode that won't get off the line (starts in 3rd?) but is fine once I get past 25 mph or so. I put it in reverse and the car bucks slightly. My question- I just need the car to get me through the next 3 mos. is there a way? AAmco said trying to change fluid would be useless. Thanks for patience and help. This forum is extremely interesting!

 

I changed fluid and filter on the road, but used what everyone says not to use. Pennzoil synthetic blend multi-vehicle (pink!). Shop has copy of letter from ZF to Pennzoil saying it was compatatble with original LT 71141 and OK as a substitute. My transmisson has never shifted so good. All hunting, thumping and rpm swings were gone in auto mode immediately after I was back on the road. Home now and have OEM G052 162 A2 on order and I will go back to it. Maybe some other stuff is OK?

 

I would love to see it and have a copy

 

Turn the ignition switch to RUN position, but don't START it .. press the gas pedal to the floor /slowly/ over the course of 30 seconds, and then hold it at the floor for a few seconds then release it slowly over the course of 30 seconds.

This has worked for several people .. it takes a day of normal driving to settle in.

 

We determined that putting nothing but the esso factory oil was very important because we knew nothing of what was going on and didn't want to take chances on a rebuild.

But with all the moves people have made to syntheitics for their gear lubes, ATF's, engine oil, etc.....somebody should try this on the ATF....

My tranny is going to need a rebuild someday soon (don't know when) I can now tell when the tranny acts a little funny and can now tell when the clutch plates are slipping/locking up.

I think I'm going to change the final drive ratio at that time also!! ;-)

 

Early this past spring, I ordered fluid and filter from Wendy (Paul knows the story). She sends 9 bottles of Audi fluid in a different bottle and color (bright red). I'm assured that this is the "new synthetic" fluid which replaces that Esso that everyone has been using. Within a couple of days I find out that's NOT the case and I've already done the filter and fluid change. Of course I freak out thinking my transmission is toast. I called ZF and had a long conversation with them about the situation. I've already driven the car about 200 miles at that point. The consensus is that if any damage was going to be done it already has already taken place, even after a couple of hundred miles. In theory, an incompatible fluid could attack the clutch material and would do so very quickly (this is from ZF directly). Off the record, they tell me that if I go 1,000 miles or so w/o any issues than I'm probably fine. I think I've gone about 15k which includes a cross country trip and have absolutely no shifting issues. Like a lot of "approved" products, ZF simply hasn't tested with any other fluids. My personal opinion is that these transmissions are probably more tolerant than we think using other fluid types but ZF simply hasn't given a stamp of approval on anything else yet...

Bob