Mercruiser 4.3L Starts - drive shaft wont move

A

Andrew's Boat

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I've got a 4.3L Mercruiser that starts up but runs very rough. It ran fine for months and all of a sudden it died when I tried to put it into gear. Now when I start it, she screams and grinds VERY loudly. I looked at the drive shaft and it does not turn when in F, R, or Neutral.


Please help.
 
Don S

Don S

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Re: Mercruiser 4.3L Starts - drive shaft wont move

I looked at the drive shaft and it does not turn when in F, R, or Neutral.
Click to expand...

Are you talking about the shaft that goes in the coupler at the back of the engine, or the PROP SHAFT, the one with the prop on it?

If you are referring to the drive shaft that goes into the coupler on the back of the engine, the the splines are gone in it. You need to pull the engine, replace the coupler, find out why the splines are gone and fix the problems.
Do you remove the drive yearly to grease the coupler splines and check alignment?
What year is theis drive, and what kind? Alpha or Bravo?
 
A

Andrew's Boat

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Re: Mercruiser 4.3L Starts - drive shaft wont move

Thanks for the quick reply Don S.

I'm talking about the shaft out of the back of the engine. It's a 1985 Alpha 1, I just bought the boat 3-4 months ago so I can only guess of the previous maintenance.
I don't have the tools, time, man power etc. to pull the engine myself, what should I expect to pay for a job like this?
 
Gary H NC

Gary H NC

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Re: Mercruiser 4.3L Starts - drive shaft wont move

Labor for pulling the engine and drive,the cost of a new coupler and probably a new drive shaft...
break out a couple grand for a marina to do it...just a guess...:rolleyes:

Plus you have a rough running engine to diagnose,..
Also the drive could be shot and that caused the coupler to go..
 
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