Hi all,

Here is a ZF 5HP24 transmission related problem where I think no one on this forum (or BMW forum) has come across, yet...

TLDR:
My transmission jolts 95% of the time when I almost come to a complete stop.

Full explanation/question:
The backstory is that I have installed a secondhand 1998 5HP24 transmission with 130.000 km's last summer in my 2001 3.2 X308 with a new filter, fresh oil (the brown-ish ZF type), new magnets and gaskets since the one in my X308 went bad (cracked valve body & broken torque converter).
I suspect the oil has never been changed on the second one since the filter had a 1998 date stamp on it.

The problem however, is when the transmission is in drive without touching the throttle or the brake pedal, the car jolts very softly (which my previous transmission didn't do). When I apply the brakes to slow down, the jolting(?) becomes more noticeable.

It is really annoying. I don't think it is on it's way out since I am driving it almost daily and it did not get any worse. Also, the transmission shifts fine, torque is fine and performance too.
This happens 95% of the time when I almost come to a complete stop. It's very rare the car stops without jolting, but it does happen!

The (engine)temperature is not an issue. The car jolts in the summer & winter when the engine is cold or warmed up. Even after a long highway drive it still jolts sometimes before stopping. I know for sure that the engine is not the problem, because the RMP's do not drop. I connected my OBDII scanner, but it didn't threw any codes or warnings. The oil level is correct (topped of on a level ground when the oil was warm and after gradually shifting through all the gears).

No weird noises can be heard other than a very soft whistle sound when shifting from P or N into D or R.
Sport mode does not affect the jolting or whistle sound.

I don't think the upgraded valve body or the upgraded pressure regulator are installed on this transmission because of the low-ish mileage.

If anyone can give my a hint on what to test next to narrow down the problem, that would be awesome.
I just finished my rear & front end suspension ($$$), so I'm hoping not to hear that I need a full rebuild .