Re: Pre alpha lower unit on alpha outdrive?
The presents of the pin indicates it's either an MC-1 or an 'R'.... The 'MR' and Alpha One boxes have the bearing flipped up the other way and the loading of the bearing is generated by the movement of the gears in the gearbox. They try to push the pinion gear (and the drive-shaft attached to it) up. The bottom of the upper drive-shaft in all the top boxes are designed to work with a lower drive-shaft of either flavour. Regardless of what you put on top of it, if the lower box has a pin in the drive-shaft, LEAVE THE PIN IN! If you remove the pin, you will destroy the lower box, very quickly.....
Chris.......
(Yes, it's for pre-loading the bearing below the water pump. That's why it's called a 'pre-load pin'.....)