[iqraceworks]

Originally Posted by LanDzia

Hey man, how was your trans after all this time?
Were solenoids a fix for all your issues?

Yep, I haven't had a single issue with the transmission slipping after I went through it and replaced all the seals and shift solenoids. Even after several 1/4 mile drag strip passes in the 10's.

Now I have a cracked piston I have to deal with...so that's another issue

[Killianbag]

Hi everyone,

Just came here to say that I have the same issue with slippage going from 4 to 5. I also can here a noise when shifting to 4 and 5th gear. I did oil change, replace oil pan, solenoids, all seals and reset adaptations hoping it would solve my issue.
Before doing this the tranny was slipping when going to 4-5 no matter rpms and load.

Now that I did all of that the shift are great when the rpms are low but as soon as they get high the shift from 4 to 5 still slips. So It did not fix the issue. The codes I have are:
-4F82 ratio monitoring clutch B
-4F8A ratio monitoring gearshift 4-5
-4F8C ratio monitoring gearshift 6-5
-4F95 ratio monitoring clutch B-E

My adaptation values are:

A pressure : -264 time: 19
B pressure : -255 time: 58
C pressure : -82 time: 4
D pressure : 0 time: 0
E pressure : 168 Time: 72

The only options it seems I have left is the rebuilt of the trans.
Was wondering what you guys think about buying xhp to increase the pressure to hope it would solve the slipping. Is it a good idea or will it make it worst ?

[iqraceworks]

Resetting the adaptations was a bad idea. How many miles have you driven the car since you reset them? It can take 500+ miles before the transmission can relearn everything....even longer if you reset them back to factory defaults.

Also, I would go ahead and get xHP....see if it helps. It's cheaper to try that than do a rebuild. Your best option is to find a low milage used transmission and put that in.

What fluid did you put back in the transmission? Did you do the proper filling proceedure? Are your new solenoids ZF brand, or cheap aftermarket ones?

[mainbearing]

With all the other parts replaced, if that was the infamous E bushing leaking then rebuild is probably the only way.

[Killianbag]

I think you need to reset the adaptation when you replace something in the gearbox. For now shift are good (except 4-5 with power) so adaptation are not causing any problems.

I’ll maybe try xhp and see if it works. I will also ask a quote for replacement and rebuild see what is best. I put the zf lifeguard fluid the one your are supposed to use and the solenoids and seal are brand new expensive ZF ones. And yes I followed the filling procedure which is a bit messy lol.

I wonder which is best between replacing the gearbox or rebuilding it knowing that the one I replace it with could have the same issue in few kilometers and that the current one just had a full mechatronic service.

[rismo]

I did not read all, but I hope my below info might be of help:


1. Diagnostic Steps:

Acquire a ZF diagnostics head or consult a certified ZF mechanic.
Use the diagnostic tool to read the complete history, which includes pressure, slip, and overheating events. The ZF transmission maintains a comprehensive event memory.
In most cases (99%), the diagnostic will pinpoint the exact issue.
2. Re-learning the Transmission:

ZF transmissions have a specific procedure to re-learn the system.
Learn more about this procedure and its importance here. https://www.bimmerfest.com/threads/t...do-it.1260472/ (The ZF PDF)

3. Understanding Degeneration Process:

Degeneration often begins with fluid overheating or misuse of the transmission outside its optimal operating window.
Once the fluid no longer maintains the correct quality, slippage begins.
Continued friction from this point can lead to accelerated degradation.

4. Mitigation Measures:

Regularly replace the fluid – either periodically (e.g., every x years) or after any sustained overheating event. Note: Your DME warning for transmission overheating may activate much later than when the actual damage starts.
You can monitor heat-related warnings either by checking the TCU directly or by OBD logging the fluid temperature. However, OBD logging only provides real-time data, so you'll only detect overheating if it happens while logging.

5. Addressing Slippage:

Review the TCU log for any anomalies.
If needed, replace the affected parts. In some cases, using tools like XHP to increase the pressure can provide temporary relief. However, once degradation starts, it's only a matter of time before more significant issues arise.
After replacing any parts, ensure you re-learn the system and adhere to the recommended procedure