E39 Gearbox Issues

[ah-singh]

Hi Forummers, been having a recent gearbox issue with my 39. Problem only appears after ten mins of driving, during shifting from gear 3 to 4, the gear would slip back to gear 3 at 3500rpm and at a standstill (traffic light) car would be struggling to move and when manual mode is activated, it directly goes to D4. Tried to drop gears but still comes back to D4. At times if I was to engage the reverse gear, a hard vibration happens before the reverse gear goes in. At cold start, no such problems encountered. Any advise ?

Cheers !

 

[Herbert]

Think your torque converter is the likely suspect.