Mercruiser 4.3 Alpha One Sound

[bloatymcbloatface]

Hey guys, first time poster here. I've got a 1987 Chris Craft Viking deck boat with a 4.3 Mercruiser and an Alpha One Gen One outdrive. Long story short, I had to get an entire new (to me) outdrive put on my boat this spring. It was taken off another boat so I don't know the history of it. Good news is that everything runs and works. Bad news is that since getting it installed by my local mechanic, I've got a sound coming from the transom area ONLY when turned all the way to the right or the left. This video has the sound: https://www.youtube.com/watch?v=i8NB0o0Pdi0&t=53s

The gimbal bearing is brand new so I sort of doubt it's that and my gut feeling is the U joint but wanted to see what the experts here thought. My mechanic said he inspected the U joint in the outdrive before he put it on and thought it looked good but he is in town and I haven't been able to get him out to the lake to hear the sound in person.

Any help is much appreciated!

Thanks and cheers.

 

[Scott Danforth]

welcome aboard.

any sound when turning full right or full left is usually the gimbal bearings or u-joints

 

[Bt Doctur]

If the gimbal bearing has not been fully seated, if it was not installed with a proper tool and damaged the U joints will contact it at full over . If the U joints are bad it will have a knocking sound full over.

 

[Chris51280]

yup, U-joints. I just did mine on the gen 1. I got Moog 315 with a grease zerk. I think was around $15 a piece

 

[harringtondav]

yup, U-joints. I just did mine on the gen 1. I got Moog 315 with a grease zerk. I think was around $15 a piece

Many U joints will fit. Most aren't

 

[bloatymcbloatface]

Thanks guys for the quick responses. This may be a silly question, but can we pull the outdrive and pound the gimbal bearing in a bit more to see if it seats better and that fixes the knocking at steering extremes or should I just get the u joints replaced...or do both? Thanks again!

 

[Bt Doctur]

Who installed it and what did they use to install it

 

[Bt Doctur]

click to enlarge

 

[bloatymcbloatface]

It was installed by a retired boat mechanic who does work on the side. I installed the prior gimbal bearing but didn't have the time to fight it this time. I don't know what he used to install it with, but I'll ask him. He seems to know his stuff, but that gimbal install seems to be a little subjective on when to quit pounding in my experience. Seems like it's there and then you give it another pound and it goes a little further.

f I've only turned it a few times at idle speed to where the u joint hit the bearing, you think I did any damage to either u joint or bearing? Thanks again!

 

[Bt Doctur]

pull the drive and look for the shiny surface, thats where it was rubbing If you see it on the outer part of the yoke the gimbal is not seated, If you see no evidence of a rubbing then suspect the U joints

 

[bloatymcbloatface]

Great information thank you! Really appreciate it and will update with what I find.

Cheers.