[james0013]

So out a month ago I changed the transmission fluid filter in my 2008 328 XI (GM trans) with 56,000 miles on it.

I used all OEM BMW parts including a new set of pan bolts as well as BMW ATF.

I did not "flush" the fluid (being over 50k) just drained the fluid, dropped the pan and changed the filter. I cleaned the pan and magnet, there was some metal paste on the magnet but it did not look excessive for 50,000+ miles. The old fluid was not burnt of overly black just a healthy dark red. (that said, I would not have like to have left the change any longer, so the "life time fluid" is a joke)

I replaced and torqued the bolts and filled with fluid per the Bentley manual (Fluid temp at 43 deg C per a scan tool). Having never done a trans without a dipstick to check the level, I had my local indy shop check the trans level. They said it was OK.

I should also add that I left the belly pan off for about a week to see if anything leaked (about 100 or so). No leaks.

It has now been about 1000 miles since the change. It could just be me but I feel like in the last 200-300 miles the trans is shifting on the hard/jerky side at low speed when engine load is increased (accelerate hard). Best way I could describe it would be a heavy down shift. The most noticeable when coasting to a red traffic light that then turns green, or a stop sign that you roll or a yeald sign with nothing coming and you have to get back on the gas. I am guessing it would be between 3rd and 2nd gear. If the revs jump about 500 to 750 RPM and there is a jolt, like drive line shunt thought the car. Then it gathers speed normally. If you are really gentle with the gas then its not really noticeable.

In addition other shifts when the revs are increased by about 500 to 800 RPM seem hard, but not as harsh as at low speed.

Up shifts from a standing start are generally fine and shifts at higher speed are fine. Also coming to a stop is also ok.

I am going to raise the car and removed the belly pan and see if there is a small leak this weekend. In the mean time is this normal? I don't remember it being noticeable before the trans flush.

Thanks in advance for any help.
James

[sk55]

you might as well do mechantronic sleeve:

i remember my mechanic doing it while doing a flush something about leaks

http://www.e90post.com/forums/showthread.php?t=238933

[james0013]

Sadly I already did the fluid change etc. I did ask the dealer about the mechtronic sleeve and the advice was that if it was not leaking dont mess with it.

[hondarayblue]

The transmission adaptations probably need to be reset. How was it driving before the fluid change? Your transmission probably thinks it's still running on the old oil and filter.

[james0013]

Originally Posted by hondarayblue

The transmission adaptations probably need to be reset. How was it driving before the fluid change? Your transmission probably thinks it's still running on the old oil and filter.

Before it was driving fine, it did occasionally do a hard downshift when slowing and then accelerating but this seems more noticeable now that before.

Is this something that will eventually reset its self (I understand the there is a learning element to the TCM) or is a reset by the dealer required?

Thanks for the suggestion!

[hondarayblue]

It can be reset using a Bmw Specific software such a INPA.

[ThatRWD]

Or I have also heard you could unplug the battery for a while.

[james0013]

http://www.e90post.com/forums/showth...x+reset&page=6

Sounds like there is a way to reset the TCM just using the car. Anyone know if will work?

[ThatRWD]

I've read mixed things on that method, recent developments suggest that it places your gearbox into aggressive shifting mode for that drive cycle. You can try it, INPA cables are $20 on ebay and INPA software is free.

JB4 is also able to reset adaptations.