I just recently convert my 300E 5 speed manual.. into 4 speed auto....
and now.. i fell there's a problem with the tranny.... the maximum speed of the car can't even reach 150 km or 100 miles
and it's reving at almost 5500 rpm at that speed

what could be the problem? is it still going at 3rd gear and it won't shift to 4th gear?? or something?