I was changing the impeller on my 1989 Force 5 hp, and when I thought the impeller was coming up the shaft it actually was the shaft that came up and out of the pinion gear down in the gearcase. The gearcase oil is clean, so I can see in there through the like 1/2 hole, but I don't see any gear teeth. Do I have to disassemble the lower unit to reconnect the driveshaft to the pinion gear?