Mercruiser 3.0 Alpha One, Upper Unit Driveshaft...

[gwpuma]

Hello Everyone~

So here is my story... Took Boat to local boat mechanic. He told me my Driveshaft was broke and #1 piston was stuck... Couldnt get motor to turn manually... So I pulled the head and found a valve laying on top of piston. Valve was bent. Luckly the valve didnt cause any damage to piston!!! So the head is currently being completely refinished at napa. And my engine will turn manually. The boat mechanic had removed the outdrive during his search for an anwser. I know NOTHING about it!!! Cant seem to find any info about upper unit driveshaft... Have no idea how to remove driveshaft... Below is a picture I took. Is it broke or do I just need to replace those top bearings????

 

[achris]

Re: Mercruiser 3.0 Alpha One, Upper Unit Driveshaft...

Man, that's UGLY!!!

Go to the ADULTS ONLY section and download the manual for your drive. All the info you're after is in there.

For that job you're going to need a press... And a rolling torque indicator, and a hand full of shims.

Chris.......

 

[jtybt]

Re: Mercruiser 3.0 Alpha One, Upper Unit Driveshaft...

Yup! Toast.

You'll need the ping-pong paddle type wrench for the upper drive castle nut and know how to set gears or get a shimming tool.


Oh, and a bearing separator.


and looks like the gears got a little chewed. You should probably dis-assemble the lower to clean it out if there's metal showing on the drain magnets.

 

[Bt Doctur]

Re: Mercruiser 3.0 Alpha One, Upper Unit Driveshaft...

Page 2-10 in this link, plus it looks like a GEN II version.

 

[gwpuma]

Re: Mercruiser 3.0 Alpha One, Upper Unit Driveshaft...

Thanks...

 

[SeattleMatt]

Re: Mercruiser 3.0 Alpha One, Upper Unit Driveshaft...

What would cause the upper drive shaft to break like that?

 

[Bondo]

Re: Mercruiser 3.0 Alpha One, Upper Unit Driveshaft...

What would cause the upper drive shaft to break like that?

Ayuh,... A lack of Oil...