i have recently put a replacement engine in my 190e, everything is running ok but it will not go into any gear on the automatic box. It is selecting reverse ok because the reversing lights ar coming on but it wont move, it wont select any gear. I managed to drive it out of the garage once i put the engine in but it wont locate a gear now. any ideas....transmission fluid seems ok, do they suffer any airlocks or do they need bleeding?