Hello everyone, I’m new here!

I have 1995 G36 Brabus imported from Europe. Original transmission 722.372 stopped working (1st gear) and was replaced with 722.369. Couple weeks all was good.

The problem: transmission downshift after 15-25 mins of driving. Basically when it reaches its operating temperature. Starts with downshifting from 4th gear to 3rd even when the speed is over 50mph. The only way to shift the trans to 4th gear is to floor the gas to 4500-5 rpms. Then it shifts to 4th gear for some time and downshifts really quick to 3rd again.

Fluid level checked, all good.

So hard to find an expert for such vehicles. Please, help!

Hi - research the Bowden cable adjustment, modulator valve, kickdown connector. There a manual here: http://www.w124performance.com/docs/mb/other/tranny_722_repair.pdf - see section 27.51 Section 1.3/1 control pressure adjustment and related shift and throttle pressure controls. The unprompted downshift suggests that the throttle pressure and/or vacuum control is not regulated properly. The clutch that is affected is the KW, but as I understand, that is a robust unit and its more likely to be an issue woth the adjustments when the trans was installed. The linked file has shift point pressures of you di find a reputable service tech who can test the pressures using gauges while operating the vehicle. See Sec 3.2/5 http://www.w124performance.com/docs/mb/other/tranny_722_repair.pdf.
Good luck