Hi I need some help here.I have a 1990 525i, service regularly.recently i change my transmission oil because there was some leakaround the gasket.I used the original BMW T oil.A week after the change, i experience a jerk each time i engage to reverse gear.My mechanic say it could be some sticky valve, he ask me to service the gearbox. I am curious why it only happen after the T oil change.it has been 3 weeks now, and there is still the jerking. Have any one with this problem. or anyone has a good mechanic for gearbox problems.thanks