Another alpha 1 prop shaft question

[RLNJR]

I've search high and low in the old posts and can't find a specific answer. I have a 1992 Sea Ray 200, 3.0 with an Alpha 1 Gen 2. Had a prop strike at idle power two years ago with the original prop which didn't have a nylon bushing so it was destroyed beyond repair. While replacing the prop with a brand new one, I noticed that the prop shaft has the normal fore and aft movement as well as lateral movement that I don't remember pre incident. There isn't any noticeable vibration while underway. First question: Is some lateral movement normal/acceptable? Second question: If not, what kind of damage have I been doing over the last two seasons? I had all of the bellows and hoses replaced by my normal mechanic last year and he didn't mention any issues. Thanks in advance.

RLNJR

 

[jestor68]

Re: Another alpha 1 prop shaft question

As I recall, the allowable vertical/lateral play in the prop shaft is 5-7 thousands of an inch, depending on the series.

That is not much. It's hardly noticeable by touch.

 

[RLNJR]

Re: Another alpha 1 prop shaft question

Thanks for the reply. While I was at the boat store today, I wandered around and wiggled all of the props attached to an Alpha unit. They all seemed to have about the same movement as mine. I took off my prop and moved the shaft by itself and there was still some minor lateral/vertical movement but, not nearly as pronounced as with the prop on. I did notice quite a bit of slop with the new stlye prop bushing even torqued at 55lbs. It is a new factory Merc prop so I'm guessing this is normal.