Missouri

Please help me quess what is happening with my 1997 A8 Quattro with 130,000 miles.

When I am decelerating on the highway from say 74 to 68 mph, I will increasingly sense the downshift of the transmission. It is a muted two part thunk. I can feel it but not hear it.

It does not always happen.

What might this be?
I am reluctant to take it into the service shop because I see them wanting to dig into this and it could be $$$.

Note: I originally posed this on the D3 forum and the suggested I try the D2 forum.

gondar

What does the tach show when your senses tingle?

tonypai

I believe PaulW said it was the torque converter unlocking. Have you ever changed the tranny filter and fluid?

Missouri

The tach shows a quick jump from 1,800 to 2,000 RPM when this occurs.

tonypai asked: "Have you ever changed the tranny filter and fluid?"
Yes I have as per Audi suggestions at the Audi dealership where I bought the car. I am the original owner.

If this is the torque converter unlocking what does that mean? Must I get it repaired? Might it fail? What might this cost?

I will take delivery of a new A8 in one month. This one goes to my twin sister. I want to make sure it is in good shape when she gets it.

tonypai

Many of the 97-99 A8s have similar problems. If you do a search on here for "transmission" you'll find all you need to know. Recently a couple of guys have gotten their trannys rebuilt for around $3000. The quality of the earlier ZF transmissions are suspect and wear out. If at 130K miles this is your first experience with hunting and clunking count yourself lucky. There have been many who've replaced them with less miles.

If you're getting a new A8 you'll probably be ok. The amount of tranny issues seem be have dropped off after 2001 but that may be because they don't have the mileage on them yet.

This from 8/2 pbarick167
I have a problem developing, and need some advice. I noticed recently that, as I coast down from speeds of about 75mph with my foot off the gas, the engine revs drop to about 1200, a small thump is felt from the trans and the revs climb back a little. Torque converter not unlocking properly? Trans fluid level? Something worse?
TIA,
Paul B


Perhaps your sister won't notice if you keep the new A8 and give her your old one. :-)

PaulW

And then picking back up again, I wish I knew why it did it and what is required to fix it, either the torque converter or it's the valve body, but that we have not figured out yet.

Missouri

If it's "It's the torque converter dropping out of lockout" what does that mean? Must it be repaired? What happens if I do nothing? Right now the car is working perfectly other than this.

What would you do if it were your car?

PaulW

What would I do? Live with it, I have for about 50K miles