Gearbox problems...

[RuiTuga]

Hi guys,

My name is Rui from Portugal and i own a 12/2002 C5 RS6 Avant since last year with 97.000 kms.

After installing a GPL (LPG) system, a Bilstein PSS9 set, the "usual" gearbox problems had knock to my door...

I've already searched a ton of forums, websites, etc... and didn't found any situation like mine... so here's my appeal for the RS6.COM community...

Here's a "small" description:

Never had problems with the gearbox until i started to hear a noise from near the gearbox at any speed/gear, like a damaged bearing (meanwhile we found out that its the middle bearing on the main drive shaft that is damaged and needs to be replaced).

In a local workshop they told me that it could be some problem with the gearbox and that the first step would be change oil/filters and then check again. After i asked them if they knew the procedure for oil change on this tiptronic gearbox they told me "no problem, we know how to do it!".

Picked up the car 2 days later and as i drove out the workshop, when passing from 2nd to 1st gear on a cross road the 1st just gave a huge push like someone hit the car in the rear. And when going from 1st to 2nd it seemed that the jumps the 1st gear as the revs up (more like a clutch slippage).

Went back right away to the workshop and asked them to check the gearbox oil level... they missed 3 lts of oil on the gearbox!!!

We made the VAG COM diagnostic and there was no errors at all.

After replacing the "missing" oil the gearbox kept doing all the time those problems and the advice from a ZF dealer here in Portugal was to make a rebuild so we took the gearbox out (along with the engine...) and replaced everything: torque converter, complete set of disks, valve body, all the solenoids, etc...

And it stayed exactly with the same problems after everything assembled!!!

We checked again all the wiring, connectors, everything! Also made a complete checkup on an AUDI dealer here and there were no errors reporting any kind of problem.

And this is why i'm asking for your help if possible.

Thanks a lot for all the help and a great 2012 for all RS6.COM members!

Cheers

[PixieVC]

The shop ruined your gearbox. You can argue that the proximate cause of the transmission failure was the shop did not properly fill and service your transmission. It subsequently was released to you, wherein it incurred fatal damage due to their negligence.

Sounds like you've got a valve body issue, maybe a solenoid. Either way, it will be an internal transmission problem. You're lucky that the car isn't in limp mode...

I suggest you sue the shop, or have them pay for your transmission rebuild. If only all of us who have the failure could be so lucky!

[DonS]

All deduction here: As the problem is the same before and after the rebuild they either did the same mistake twice or the missed the problem during the rebuild. You might want to determine what the repair shop did NOT replace during the rebuild. The problem may be external to the gearbox...?

Sorry for the troubles and good luck!

[Chung]

also you might want to check out this post http://www.rs6.com/showthread.php/0?p=225115

[4everRS]

If the grinding is coming from inside the gearbox, you could take off the pan and check the magnets for debris. If there's no debris or very little, the grinding is probably coming from the shafts.

If the slipping is still happening, add more fluid again.

Not sure which is the big concern for you right now, .... Both?

[RuiTuga]

Hi guys, thanks for the replies!

@PixieVC: The shop assumed the error and the guys from ZF already rebuilt the gearbox but the problem with the shifting (1st and 2nd gears) remains. We've already tested also a new TCU and stills the same...

@DonS: They've inspected twice the gearbox after the rebuilt... and didn't found anything strange... i'm more like to a transfer case or diff problems... but they checked oils, refill them and stays exactly the same...

@4everRS: Well, they didn't found any debris after the rebuild so... i'm more concerned about the gearbox problem... the grinding i can handle with louder music :-)

Think that the guys from ZF will take out the gearbox (again) and send it to ZF factory to inspection and tests on the bench.

Thanks guys again for the help!

[RuiTuga]

Solved!!!

After 3 months the ZF dealer in Spain finally discovered the problem!

It was a damaged flywheel that works along with the servo on the 1st gear. It seems that this one was rotating in both directions when it should rotate only in one direction and block the movement on the opposite way.

Not a very technical description but that's what i could get from them.

Cheers to everyone and thanks again for the posts!