Drive Shaft Worn?

[masonh]

I'm working on the outdrive for a 1976 StarCraft Islander. Engine is 165HP, outdrive is Pre Alpha Mercruiser - number from inside of gear housing is 1623-5412.

Does anyone know the machine tolerance for the surface where the drive shaft goes into the upper unit? The surface marked as .879 in looks a little worn and there was some water in the upper gear case so I am chasing out possibilities. This looks like the surface where the shaft goes through part #10 (SEAL, Oil, DRIVE SHAFT HOUSING - LOWER). I want to make sure I have checked this close before putting it back together.

Thank you!

 

[achris]

That raised section on the top of the drive shaft for your MC-1 drive is a speedie sleeve. At some stage in the past the seal has worn a groove in the shaft and that speedie sleeve has been fitted to alleviate the problem.

One more thing. When you assemble, do not put the o ring in the groove at the top of the shaft. If you do, it will hold open the lower seal in the upper housing and allow water into splines and corroded them out.

Chris

 

[masonh]

Chris, thank you for the advice and for taking the time to share this information. I'm a little concerned that there is sign of work done in the past and a little water in the upper gear case continues to be a problem. Moving forward, I think the best solution is to machine the surface and have a metallurgic or ceramic coating added that covers a wider surface area. Also, I will take your advice and not install the o ring in the groove.

I remember when I pulled off the lower unit and looked at the o-ring it appeared a little fried around the interior, and the shaft pulled out effortlessly.

Now I need to find a machinist. Your thoughts, is that a good way to go?

 

[achris]

...Now I need to find a machinist. Your thoughts, is that a good way to go?

If you can find someone to 'metal spray' that surface and remachine it, yes, that is the best way to go. Only issue with that is that you will need to remove the shaft from the housing.... And for that, you need all the tools.

Chris.....