Garage Cabinets, Garage Storage, and Garage Organization

I have mercedes E240 1998,

Recently My car radiator leaks and water mixed with transmission oil. I overhauled the transmission, changed few components, i.e. valve body, primary pump. clutch plates.

Now my only moves for 5 minutes and then stops, engine is runing but slecting D or nay other position the gear lever car does not move.  If you switch off the engine and restart after say 2 minute car moves and gear engaged but after 2 to 3 minute stops [no gear engaged] with engine is working

I wounder If any one can help me