Ok, I had mentioned this in another post but thought I'd start a new post for this problem. In servicing the water pump impeller on a '76 mercruiser #1 drive Serial #4432173, I learned about the washer that is supposed to be on the shift shaft in the lower unit before mating it back to the upper. This washer is there to keep the shift shaft in the upper housing in position & prevent it from dropping down out of the shifter mechanism that comes thru the gimbal. There was no such washer in the lower when I pulled it off. As it sits right now, with the lower off, the upper shift shaft has dropped down out of where it mates to so I can clearly see what is going on in terms of the washer & what it's job is. I'm going to slide the lower back on & see if the upper fits in its proper position. If it stays up & engaged with the piece coming from the gimbal I'm guessing I'm ok. If it does in fact drop down, can I just put a stainless washer of the appropriate size to keep the upper shaft in place in there opposed to ordering the original? If the thickness of the washer is sufficient to keep the upper shift pieces engaged & it doesn't interfere with anything else, would it matter if it wasn't the original one? Thanks. Jim.
