RPM fluctations

[mcs]

Originally Posted by vajper

I'm really interested in your findings!

I took the car for a proper adaptation ride today. Followed the four separate adaptations in the SSP 385 and indeed, I got adaptation count for all clutches. It's quite fun when the documentation matches the real world -- was lacking adaptation on the clutch related going 1->2. After getting this in place, the shift was a lot smoother.

Unfortunately I still see slippage, especially on gear 1, 2 and 3. VCDS indicates torque converter is not locking until reaching higher gears. What I see though, is that the TC lock goes from Open to "Torq. conv. reg" in the slippage cases. EDIT: Removed some stuff. REG mode seems to be a valid mode where some slippage (max 512rpm?) is allowed to handle smaller throttle changes. So, instead of shifting up/down, it slips a bit. Something about being fuel efficient. Also something that seems to be a hazzle when pulling a trailer... Maybe this is as good as it gets?

Adaptation values are not out in the blue. Unfortunately I don't have the old values from before resetting the adaptation but as of now, no value is outside the limits. Still I'm thinking leaking seals may result in the TC lock not engaging.

Anyone with experience on this?

I am told the gearbox does slip the clutchpacks on purpose to make it smooth. It is considered normal operations. The 4 tubes however, control the amount of fluid supplied to the clutchpacks I am told and they get hard as well as compress to leak fluid internally. This won't help things.

[vajper]

I have ordered new rubber thingies, new gasket to the tray plus another seven precious liters of ZF LifeGuard 6. If I get all the parts for next weekend, I'll give it a try. After doing so, I will run through the four recommended steps in the SSP. I'll report back later...

[mcs]

I just picked up the car from the gearbox place.

It is a totally different machine to drive. So smooth. Seriously smooth.

The rev hunting on the overrun has vanished. The gears downshifting are not noticeable as the car slows to a stop.

I was told the internal seals were incredibly worn, and this would cause many issues as the clutchpacks cannot get the correct fluid amounts due to internal leaking.

However, it is all done now. Recommend these parts are changed every 100,000 klms.

Mike

[vajper]

Oh, that is SO interesting to hear! I'll try to do mine to in the weekend. Promise to post some pics.

[vajper]

The Swedish postal service seems to have lost my spare parts so no work this weekend. Darn

[mcs]

I've done about 750 klms in the car since the box was serviced now.

The service place was unable to reset the parameters for the gearbox learning, which I have heard of before in very early D3's. It should adapt itself in time in any case, which it seemingly has done.

The box is much smoother to run down the gears to first, and also engages the TC Clutch without any rev bounce on the overrun. Everything seems to be good.

Mike

[vajper]

Changed my bridge seal and the four rubber thingies this weekend. Reset the adaptation and ran through the initial recommended cycles from the SSP. After that, not that much driving.

So far it is behaving better but still I experience more TC slippage on 3rd gear than expected

It still seems like the shifts 2->3 and 3->4 is happening in "two steps". I get first one motor RPM and then another. Like there is a "middle gear". I don't think I have seen the TC ever closing on 3rd gear, even when really pushing the throttle to max. Guess this might be one of the clutches being worn out...

I've done what I can, will follow up the behavior closely the next coming months.