Transmission and transfer case fluid change/reset - BIG difference

[wpoll]

Originally Posted by X5chemist

Doesn't the X-drive do an auto adjust every time it's started? I thought I read it here.

It does re-calibration at shutdown. Not sure if it does anything at start-up - the TIS says nothing about that: -

Calibration sequence:
When terminal 15 is OFF, a calibration sequence is performed. During this calibration sequence, a certain angle setting of the VTG actuator motor has a corresponding locking torque assigned. The effects of wear are also taken into account when this is done.

The multi-plate clutch is closed fully and separated once during this calibration sequence. When this happens, the current draw is measured at the respective angle setting of the VTG actuator motor. This determines the beginning and end of the closing movement for the multi-plate clutch. The angle setting is recorded by means of the integral incremental sensor in the VTG actuator motor. These values are stored and are used as data when the car restarts.

The Oil Wear Adaptation that should be done in an xDrive ATC-500 when completing a fluid (power divider oil) change is to reset the oil wear and clutch friction adaptations. The clutch friction co-efficient changes with fresh oil so the system needs to be re-adapted to allow for this.

Makes a BIG difference!! Hence this thread.

[crystalworks]

FWIW, my 6HP26Z in the 4.8is was exhibiting bad 2-1 downshift kick (the infamous being rear ended feeling) for a long time. I learned to drive around it and thus avoided it 99% of the time.

Anyway, I used the Valvoline Maxlife ATF Full Syth multi vehicle, paired with bridge and tube seals, followed by a adaptation reset @ ~120k miles if memory serves. Trans has been perfect for 3 years and 10k miles. Having experience with most of the fluids ppl use in ZF transmissions... the Valvoline is my favorite (the thickest). I've used Pentosyn, Lubri Moly, Red Line, and of course Lifeguard 6 (the thinnest).

BTW, I have 7L (I think, maybe 6) of ZF LG6 here that I'd let go for cheap if anyone local was interested. I'll never use it.

[sixness]

Hi Wayne, Why did you decide to change the seals in the transmission, was your car doing anything to prompt you to do this? Any codes thrown?

I am asking because the issue I was having which felt like a misfire when cruising at around 110km is more likely to be the transmission hunting between 5 & 6th. I have also notified the car is slow to engage reverse after its been sitting a while. The 6HP26X filter and fluids were changed 40K km ago and this issue only started about 10k km ago. Its more of a occasional annoyance as the car hasn't ever gone into limp mode, it occasionally throws a 4F86 or 4F80 Ratio Monitoring Error.

Did replacing the seals fix your issues?

Cheers
Chris 2005 X5 3.0D 334K km in Oz

[wpoll]

Originally Posted by sixness

Hi Wayne, Why did you decide to change the seals in the transmission, was your car doing anything to prompt you to do this? Any codes thrown?

I am asking because the issue I was having which felt like a misfire when cruising at around 110km is more likely to be the transmission hunting between 5 & 6th. I have also notified the car is slow to engage reverse after its been sitting a while. The 6HP26X filter and fluids were changed 40K km ago and this issue only started about 10k km ago. Its more of a occasional annoyance as the car hasn't ever gone into limp mode, it occasionally throws a 4F86 or 4F80 Ratio Monitoring Error.

Did replacing the seals fix your issues?

Cheers
Chris 2005 X5 3.0D 334K km in Oz

I had a slight leak on the mechatronic seal and since I was opening it up to sort that, I figured I would replace the jump seals and bridge seal too. As you do. No other reason, other than the hope of extending the life of the transmission.

I have some slightly odd behaviour from my trans - it's certainly not perfect but its still pretty good for a trans with over 280,000kms. The hard 2-1 shift has recently become more obvious, it holds second gear way too long and it does seem to hunt a little between 4-5 at low rpm when cold (changes up too soon and engine lacks the torque - so turbo issue?) - might need to sort that soon, although I have yet to decide how I might do that!

But on the whole, it still drives very well and I'm still very happy with it.

I doubt replacing just the seals will fix your issues. I hear that these trans can suffer loss of solenoid performance and respond well to solenoid replacement but I'm not sure of the exact issues at play here.

[X5only]

I sometimes get that kick in the butt especially going uphill and stopping, and then when taking off the car gets kicked in the butt real hard . Trans service has been in my to-do list for years. I got all the parts except the trans fluid, just the time that is elusive . I did the same service on my E92 years ago with great results (reverse gear would slip occasionally).

[haigha]

A note to say that Wayne and I both ran into a problem with the bridge seal (leftmost one in his picture). The ones we received had two tabs that made it so they wouldn't fit into our earlier revisions of the transmission. See this post and its thread for details:

https://xoutpost.com/1232995-post6.html