I have a 92 Geo Tracker with a 5 speed. The question or problem I have is that there seems to be very little difference in speed or rpms between 4th and 5th. It doesn't have a tach. so I can't see if there is any drop in rpms. It also seems that it is tacking about 4000 at 45mph. Could it be that it is not even in 5th when I shift from 4th to 5th. Also could it be that I have a automatic transmission rear end or would that have an different affect. The clutch is not slipping.