Rezern

Hi all

First post on this forum, hoping you guys could help me sort out my transmission problem for a smooth ride.

I have a couple of different conditions that concerns me regarding my transmission. All conditions are the same whether the car is cold or varm.

It's a 2003 A8 with full service history (book) 3.7L engine and transmission code GQE and it's been driven 98k miles

1. during downhill driving with no gas applied in Auto (normally in 6th gear) the RPM jumps up and down with 500-700 RPM. When gas pedal is applied just slightly it will immoderately stop and behave normal.

2. During uphill driving in 3rd gear with some gas applied, it will jump up and down on 500-700 RPM, this will continue until much more throttle is applied and it will the remain normal until throttle is released.

3. Gear change from 2->3 with slight throttle applied will result in a rough gear change almost making the car jump a little. A big "thump/bang" sound is heard at the gear change, with iI think is from the driveline and not the transmission itself.

Have spoken to my local dealer about my problems and we have discussed solutions back and forth.

We did check for software updates on the transmission but none found.

Tried to uppdate the MMI software, but that failed due to a faulty CD changer, I don't know if the MMI update could change anything? (If anyone know where I could find cheap CD changer or how to possible repair the one I have, please give me a shout

The last thing I have discussed with the dealer is a complete oil and filter change on the transmission including an oil flush(2500$).
If thats not gonna do any difference the dealer says I have to change the torque converter.

I have no fault codes on the transmission or the torque converter, so I'm a bit skeptical about the whole change of the TC, since I expect it to cost an arm and a leg.

What do you guys think could be the problem behind these conditions?
Do you have any recommendation on how to fix it?

mishar

Welcome!

Try first just all simple ATF change. You need 6 liters of ZF Lifeguard6 and any oil change shop can do that. If that helps you should do it once more in order to replace more ATF (there are close to 10 liters but only 5+ can be drained).

TSHong

+1, I would try a fluid change first since it's the most inexpensive possible repair.

The MMI update will do nothing for your transmission. The MMI is for your entertainment system.

Rezern

Thanks for your reply

Would one benefit from flushing and changing the filter? I would imagine it could have an postive effect possible.
Would then be able to change all the oil at once instead of having two oil changes. and possible filter change later.

Regarding the TC the dealer talks about, should'nt that throw an error code of some sort? I have VCDS and I can't find any faults on either TC or transmission. Dealer also checked for faults but none found.

Dont know if it's relevant but it does seem to be a bit better in "manual" mode, but the change from 2->3 is the same in all modes.

Other than the issues stated in first post transmission works fine.

MP4.2+6.0

If it's Euro (given the 3.7 motor), I realize it could well be a D3 in 2003, especially given the MMI reference. If it is a D3, it should have a six speed tranny. If it's still a late D2, it would have the 5 speed tranny. Different designs and diagnoses, and with the older 5 speed much more trouble prone by 100K miles. BTDT. If you have a D2, you would want to post on that board. Or rather, just search it. The issues and solutions are well plowed for that generation.

But in either case, per the other replies, a fluid change is often in order to try to get it shifting better for not too much money. The fluid spec varies from the five speed to the later one too IIRC.

Rezern

It's a D3 with 6 speed transmission and it's an european model. So I should be in the right forum.

So far I have not been able to search up any known faults on theese transmissions. Might be me being a poor seacher.

To be curious could this strang behavior of the transmission be related to other faults or components?

Think I just have to go for the oil change / flush procedure in the first instance given your replys.

MP4.2+6.0

The D3 transmissions seem quite reliable. Very few posts about issues requiring more than a fluid change during the 6+ years I have been on this board, and knowing on the other hand the common issues with the D2 and C5 transmissions.

Thus, yes, just try a fluid change. You mention the $2500 from the dealer for a full flush. Instead, just get the fluid drained and replaced the conventional way, presumably with a good independent mechanic who knows Audi's (or yourself, if you do). The fluid needs to be monitored temperature wise during the fill, so be sure the shop has the equipment or VAG-COM/VCDS. It would be better to change filter too by your age/miles, but some skip that step. I try to change the filter, at least at the first major drain or with a known issue.

You can just do a drain and replace with your existing fluid with either the Audi OE fluid or ZF LifeGuard 6--referred to as "Gold" for its color There is also an Audi TSB that deals with rough shifting on the U.S. 4.2's, but to do that you need a more though/complete fluid replacement. The TSB is also published for Jags and BMW's using essentially the same tranny other than RWD instead of AWD. The TSB involves both that fluid change and a re flash of the tranny control unit (TCU), but many have had success with just the fluid change, either to Blue or just sticking to Gold. The TSB process uses Audi OE fluid known as "Blue" which was the factory fill for the W12; it is also sold as LifeGuard 6+. More expensive than Gold. Perhaps your dealer quoted the "Blue" complete replacement approach. If you did at least two basic drain and replaces, or preferably three, you could get to about the same as the flush approach--you have to get the extra fluid stuck in the torque converter and elsewhere that takes several drains to get most all of the old stuff out cumulatively.