Crank shaft boot

Jyocum12

Cadet
Joined
Jun 4, 2008
Messages
13
I have a 87' mercruiser 120 and i noticed theres a rubber boot on the main drive shaft going to the outdrive that is dry rotting. Is this a problem or is it just to cover the shaft. I talked to some guys at work and they said they had a boot that went bad on the outdrive and it almost flooded there boat. Any ideas or thoughts would be helpful.

thanks
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,304
Re: Crank shaft boot

If you plan on using it as a planter, then it not aproblem.
If you plan on putting in the water, then yes it`s a problem because it will let water in and sink the boat.
 

Jyocum12

Cadet
Joined
Jun 4, 2008
Messages
13
Re: Crank shaft boot

Thanks, do you know what it is called and is it expensive to get fixed.
 

Jyocum12

Cadet
Joined
Jun 4, 2008
Messages
13
Re: Crank shaft boot

Does anyone know what this part is called and how hard it is to replace.
 

Fishermark

Vice Admiral
Joined
Oct 19, 2003
Messages
5,617
Re: Crank shaft boot

It's called a driveshaft bellows. It is not especially difficult, but I wouldn't classify it as easy for someone who has never done one.

I don't have a link to the OEM manual, which would be helpful for you, but here is a page that will probably help:
http://www.mercstuff.com/howdoi.htm
 

Tjdunklee

Cadet
Joined
Jun 6, 2007
Messages
8
Re: Crank shaft boot

I just finished replacing the bellows (shift and crankshaft/u-joint) on my Alpha 1 outdrive. It wasn't too hard, just time consuming. Follow the directions in the manual very carefully and take your time! Do it right the first time and you will thank yourself later! I also did the lower shift cable as long as I was taking stuff apart and the boat now shifts like a dream.
 

Fishermark

Vice Admiral
Joined
Oct 19, 2003
Messages
5,617
Re: Crank shaft boot

I don't think I've ever gone into a well stocked marine store that didn't have one one the shelf - many times even out with the "over the counter" stuff. Every web site that sells marine stuff will have what you need. Take your pick! ;)
 
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