The speedometer drive and driven gears are part of the transmission, and are matched. The drive gear is on the output shaft, the driven gear mates with that gear, but should be easily removable without disassembling the transmission- or removing it from the vehicle.
Jss1956, if you are trying to remove the speedometer drive gear, yes, you have to drop the drive shaft and remove the transmission tail housing- after you drain the oil from the case. Then you need a new gasket and seal for the tail housing.
I don't remember if the drive gear is a press-fit on the shaft or not. I can probably find out, but maybe someone else can answer that.
Harvester
