Mercruiser alpha 1 GEN 2 prop wobble tolerence?

[indy440]

Can anyone look in the book and tell me what the allowable prop shaft wobble is and where it is measured from (tip of shaft vs. base of shaft?). The boat is a 1993 Larson with a 3.0L 4-cylinder.

I think I have a bent prop shaft.

 

[JustJason]

Re: Mercruiser alpha 1 GEN 2 prop wobble tolerence?

I'm not going to dig up the book to answer your question, but I will tell you if you can see it with your eye, then the shaft is bent. Just a guess but by the book the tolerence is something like .006 .008ish. Very small. And usually so small you should not be able to see it by your eye unless you have a machinists eye.
So again... if you see a wobble, then you should have it repaired before the wobble takes out the whole lower on the drive.

 

[Don S]

Re: Mercruiser alpha 1 GEN 2 prop wobble tolerence?

Look in the Adults only sticky for a link to the OEM service manual #14 for your drive. Has all that good stuff in it.
Here is a quick pic from that manual.

 

[indy440]

Re: Mercruiser alpha 1 GEN 2 prop wobble tolerence?

I can measure the end of the shaft wobble probably 1/4" with a tape measure.

This is a big problem. I just bought the boat from a Marina yesterday with no warrenty. I have not taken it out yet, I wanted to change the lower unit oil before using it tomorrow and thats when I noticed the bent shaft. I drained the oil and it had some milky swirls in it (indicating water, probably a worn seal from the bent shaft). I already called the dealership and left a message on the machine but they were already closed for the day. They open again tomorrow.

 

[indy440]

Re: Mercruiser alpha 1 GEN 2 prop wobble tolerence?

I just measured with a dial indicator.

.011 at the base of the shaft

.068 at the tip of the shaft.

it is not hard to see the tip wobble just by eye.

 

[JustJason]

Re: Mercruiser alpha 1 GEN 2 prop wobble tolerence?

well .011 is over the limit. Take it back and see what they will do for you.

 

[indy440]

Re: Mercruiser alpha 1 GEN 2 prop wobble tolerence?

I dont understand how to open the service manual in the adults only forum. I can only open the "notice" file, which is just the first 14 pages of the manual. What am i doing wrong?

EDIT: nevermind, I figured it out...