470 stern drive fear

[spoticus02]

I changed out my raw water pump on my '81 Beachcraft, and had the lower stern drive out (many, many times...) due to shifting and overheating problems, and I can now do it in my sleep. Troubleshooting from the things I know work, I've traced the problem upward into the upper stern drive. When I get the lower drive shaft aligned and the shift coupling set just so, I know that the splines are mating correctly, and as I turn the lower drive shaft clockwise to line them up, I know that the prop is turning correctly. Now, I'm pretty sure that the upper drive gears are not even turning, so my new water pump isn't even spinning, leading to the overheating. With the lower drive out, I know the shift cable is working fine since the coupling finds all gear positions easily, and after a correct install of the lower drive, also shifts smoothly. Now I'm trying to find a starting point for the upper drive, and the fear has set in, both dollar-wise, and time out of the water. I don't think the upper gears are stripped since the lower drive shaft is so touchy about alignment going up. Any ideas?

 

[Don S]

Re: 470 stern drive fear

My guess is you have a stripped out coupler splines.

 

[spoticus02]

Re: 470 stern drive fear

You mean the lower coupling that I aligned the lower stern drive to? That would be incredibly easy. Just a cotter pin to change that out, right? But why wouldn't the drive shaft at least turn the pump impeller in neutral though, unless you're talking about a different coupler? I think I read something in my Clymers about an upper coupler, but how hard is that to get to? Thanks for the post!

 

[Bondo]

Re: 470 stern drive fear

It's the Engine Coupler that Don is talking about,.......

It's bolted to the Flywheel,+ accepts the splined shaft of the Upper Unit......

 

[spoticus02]

Re: 470 stern drive fear

Ooooh. That repair looks like the whole engine has to come out to get to the flywheel housing and the engine coupling. Looks easy enough if it were already accessible, but without a motor lift, gonna be hard. Any idea on what a shop might charge for this one? Not great news, but makes total sense. Thanks again gents.