S4SLVRBLT

Hello all. I am new to this forum but not new to audis. I have a 1999 A8 Quattro and a 2001 S4 6sp. My question for a problem that has gotten worse in my A8. What happens is I am driving around town in drive at 35 - 50 MPH and the transmission will hunt between 4th and 5th gear up and down. The RPMs of the engine will surge and fall with this and it feels like the car is running rough. If I punch the throttle the transmission kicks down and the car accelerates fine. But if I lay off and drive leisurely in Drive, the transmission will continue to do this surging up and down. I am just out of warranty thru Audi Assured by two weeks. The problem was there for some time but has gotten more noticeable lately. Does anyone have any ideas? I am in Riverdale, NJ. Thanks.

John

tonypai

You have a common problem of the earlier A8s. Have you changed your transmission fluid and filter? That did wonders for my car. It cost around $200 for an independent mechanic to do it. There should be a procedure on www.audipages.com.

Return 4 Deposit

Quite a few 97, 98 and early model year 99 ZF transmissions have this issue. How many miles on your A8? It seems to show up around 80,000 miles or so and get progressively worse.

The fluid/filter change is a must do item. See www.audipages.com for the details. This may lessen the hunting. Do this asap.

Some have had luck using VAG COM to recode their trannys to sport, but it seems the ECM "learns" to hunt again. Some have learned to live with the hunting, some have put new transmissions in.

Tozo is the man and has experiemented with a variety of fixes, different synthetic ATFs, valve body work, etc. Hopefully he will chime in with his experience.

Many other forum members have dealt with the hunting issue as well. Set aside about 45 min and do a forum search and you will see what I mean.

Good luck - have you thought about trying to get it covered under Audi Assured? Only two weeks out of coverage? Dayum It!

badgerbolt

No good news for you. You are doomed like the rest of us. I have a 99 A8 and can't stand to drive the car anymore. I did the flush around 75K. For some this helps briefly but it's only a matter of time. Audi knows this as does most transmission shops. In fact I sure many people are aware of this by now. Why do you think used A8's have one of the worsed depreciation records in the auto industry. The 97's thru 99's have a 100K transmission and then you spent $4,000- $5,000 to replaced it.

audilvr

I would think $300-$350 is closer to the mark at an INDY mechanic. $13/liter for Pentosin ATF, $30 for the filter, 2 hours labor++

I paid $285.

ryoung

What happens if you drive in Tip mode and just leave it in 4th?

The S8 has lower gearing, but even on Interstates I sometimes stay in 4th in Tip if I've got less than five miles to drive. In the S8, 4th gear is good for 144 mph; and in the A8, 164 mph (which is well above the A8's top speed). You'd sacrifice some fuel economy, but if it works, the reduced grief would probably be worth the cost. Even for me, the 25% less shifts is worth it as an insurance premium for less wear-and-tear on the tranny.

Or is it the torque converter locking and unlocking while staying in the same gear?

<img src="http://pictureposter.audiworld.com/17157/speed-in-gear.jpg">

skiracer

I'm fairly sure the hunting is the TC locking and unlocking.

PaulW

I don't like driving in tip because it doesn't downshift automatically unless you have a huge throttle position angle or the speed of the vehicle has dropped significantly.

Driving in 4th on the highway makes it more bearable.

tozoM8

The TC locking/unlocking. Do a filter and fluid change and put a bottle of red Lube guard in it.

tozoM8

On older cars when the TC went out they said your overdrive is broken. The four speed automatic was only three speed and overdrive ( TC lockup ). On our car if you accelerate slowly, it feels like 6 speed ( 5 speed and lockup ).