fear of bent shaft

[1man2beat]

O.K. I am new to all this boat stuff!! I have a 1986 Searay with a 3.0 Merc 140. I had to rebuild the wood motor mount. So I hooked a com-a-long onto the engine and relieved the pressure of of the wood and the metal front mount so I could remove the bolts. This would allow me to get the wood mount out and replace it with a new one. I feel that I have not lifted the engine to high to bend the shaft. My question is: How high would one have to lift an engine to bend the shaft? Do you think that in fact I did bend the shaft?

 

[Don S]

Re: fear of bent shaft

Don't lift it at all unless you remove the drive. You won't bend the shaft but you could damage the coupler. Then, just lift the engine enough to take the weight off the front mount. You still have two rear mounts you don't want to flex too much.
Once the mount is off, fix your wood mount, put the motor mount back on, and do an alignment with an alignment bar.

 

[1man2beat]

Re: fear of bent shaft

Will this alignment test tell me if the coupler is damaged?

 

[Don S]

Re: fear of bent shaft

It might, it might not. I have never lifted an engine to see how high you could go before something was damaged.
http://forums.iboats.com/mercruiser...utdrives/engine-alignment-how-tos-443992.html

Typically, you pull the engine out, do the fiberglass work then put the engine back in. Keeps all that abrasive FG dust out of the engine.

 

[slag]

Re: fear of bent shaft

Last year I replaced the front mount on my boat. I stuck several pieces of 2x4 under the oil pan and then lifted the engine and had my son wedge a smaller piece in to remove pressure from the front mount. I then created a new front mount based on dimensions of the old one and glassed it in. I then lag bolted the motor back to the new mount after removing the 2x4 blocks and it ran perfectly all last year.

 

[Don S]

Re: fear of bent shaft

So you are lucky, how do you know the engine was in alignment when you were done? It may take 2 years to destroy the coupler because it's out of alignment some, and not a whole lot.
Pulling the drive once a year and checking the alignment is just simple preventive maintenance. And fixing the mount and not checking the alignment is not a good practice.

I have drove a a Vette down the highway at 140 mph, but I really don't suggest others try it just because I was lucky.