i took off the lower unit to fix the gears. im not sure ill be able to put it back on with out knowing how things work in there.so how exactly does the water get pumped. and what does it have to do with the gears, because even though the prop wasn't turning, the water was still pumping.thanks.
What make?model etc. that is the first step,then contact maker for details
did you put the dot of adhesive on the Keyway to hold it from slipping out of place ? Are the pump plates worn around the impeller ? If you just replaced the Impeller and NOT the whole housing, and plates, that is NO GOOD, you must replace the whole unit.
The drive shaft turns with the engine and turns the impeller which picks up water and pushes it into the power head and exhaust There is a pick up in the foot
The driveshaft is always turning. A pinion gear at the bottom of the driveshaft spins the forward and reverse gears, which are freewheeling (in opposite directions) on the prop shaft. The clutch dog is splined and/or pinned to the propshaft, and moved forward (to mesh with the forward gear) or aft (to mesh with the reverse gear) by the clutch dog cradle, which is moved by the up or down motion of the shift rod. The backside of the forward reverse gears are machined with square corners that mesh with the clutch dog. So, the engine turns the driveshaft, the driveshaft turns the gears, the gears turn the clutchdog, and the dog turns the propshaft. Meanwhile, as mentioned, the drive shaft, which is always spinning, is also the water pump shaft. The water pump has a neoprene impeller in a chromed housing; a very tight fit -- the vanes have to be bent over to fit. The center of the housing is offset from the shaft, so the compartments where water is drawn in get smaller as they rotate toward the discharge, which provides enough water pressure to force water through the engine even at idle speed. The impeller is fit so tightly into the housing, that it will generate enough heat to melt and break up without a source of water -- it only takes about 30 seconds of dry running to seriously damage the impeller. to fix the gears, you have to use a gear puller to pull the propshaft bearing carrier. The reverse gear will fall out. Reach in with a long box-end wrench to remove the pinion gear from the driveshaft, and pull the driveshaft bearing housing out with the driveshaft. When you remove the shift rod, the prop shaft, forward gear, clutch dog etc should be accessible. There's a lot of complicated steps to accomplish each of the above, and some critical measurements with near-zero tolerance. Don't do it without a factory service manual in hand.
