Our 1999 Audi A6 Quattro 2.8 with automatic transmission recently developed a rough, clunking shift into reverse. It also frequently hesitates or initially refuses to upshift and when moving at road speed sometimes seems uncertain as to whether to upshift or downshift. It was checked by an Audi dealer but, according to him, it basically performed flawlessly while in his hands although he did say that it did shift "a little rough." His suggestion was to bring it back for an overnight stay so that it could be driven when totally cold.

In the meantime the problem is as bad, if not worse than before. This time not only are the other problems present but after temporarily refusing to upshift it will often go into gear with a harsh crash and jerk.

Can anybody give me some ideas as to the most likely cause/s for this erratic shifting? Any help will be greatly appreciated.

 

from what you discribe, my first impression is an internal failure of the trans. is this an auto manual trans? if yes then you must have tried shifting manually, can you tell us your observations?

 

Thanks for your quick response kimi. It is appreciated.

To your questions--It is a Tiptronic. On the occasions that I have tried manually shifting I have experienced essentially the same behavior. Sometimes it will not upshift but continues to rev. Twice I pulled it over into manual when it was revving at about 15 mph in automatic. It nearly threw me through the windshield as it squealed the tires to a slower speed. Fortunately, the seatbelt was working.

I am certainly not an expert when it comes to automobiles so please bear with my faulty descriptions.

 

am not an expert either and i think you are doing just fine. did your check engine light come on? if yes take it to Auto zone for decoding. it is free and may rule out electronic problems associated with your trans, if not then, an internal trans failure should be on top of your differencial diagnosis list.

 

Hi snurb, how about your oil transmission level? it can be a problem.

make sure your oil transmission level is ok.

 

Too bad it is nearly impossible to check your trans fluid yourself, I have had a few "rough" shifts in mine as well

 

Thanks for all of the informative input kimi, andry, and 2000 2.7t. It's great!

I assumed (perhaps wrongly) that the Audi tech checked the transmission fluid as a first line diagnostic item. In a phone call to the tech prior to the aforementioned appointment I specifically asked if I could check the fluid as a precaution before making the 90 mile drive to the shop. His reply, "Not likely. It is very difficult for the average driver." I will phone the shop to ask specifically if they checked later this afternoon.

Just to catch everyone up on the latest details and my puzzlement. Last night the short drive that my wife took the car was terrible. She reported that it would not upshift in automatic and her speed was limited to about 20 mph. It also shifted violently.

This morning I took it for a short drive to check out the manual shifting. After an initial clunking shift from reverse into 1st it shifted as smoothly as whipped cream through the remainder of the gears (manually) both up and down for an eight mile run. Feeling a little more confident, I turned and used the automatic for the eight miles back to the house. Again, it ran beautifully with nary a sign of trouble. To me, that would seem to limit the tech's theory that the rough shift might be linked only to cold starts. However, it doesn't yet tell me WHAT the trouble is.

I did forget to mention that the ABS light had been on for awhile and that the Audi dealer has an ABS module on order for the car. Somewhere in this or another forum I read a thread that suggested that a brake switch might someway be related to rough shifts. I would like to hear your thoughts on that idea, please.

 

i assume your check engine light is not on, despit that i will suggest you go to Autozone tell them your check engine came on, this will lead them to put the car on the computer which may reveal a code. this will be for free. i am just trying to rule out a possible electronic miscommunication with the trans. otherwise i will stick with a bad trans as primary Dx

 

kimi, you are correct in your assumption. Engine light is not on.

I will definitely go by Autozone this evening or in the morning. I like the idea of ruling out different possibilities.