Cutlass bearing spinning in shaft log...>

[Heron]

While the boat is out of the water for paint, I've been going over things below the waterline. Messing with the prop the other day I noticed some side to side play.... Turns out it was not a worn cutlass bearing, but the entire bearing spinning in the log. No idea how long this has been the case as this is the first time out of the water since the survey a year ago. The surveyer noticed some slight play but didn't pick up on the true issue assuming it was a slightly worn cutlass bearing. A simple spin of the prop would have shown what was happening. Pulled the 2 set screws and found the ends rounded with no divots on the Bearing to keep it from spinning.
Secured some new set-screws (Mcmaster.com), drilled a divot though the holes into the Bearing, and installed new Pointy Set-screws. Bearing now locked from spinning with no play evident. Kind of an odd problem, but worth a look see when your boats are out of the water...

 

[RT Firefly]

Greetings,
Mr. H. Hmmm...Hard to tell without removal of the cutlass bearing but is the movement due to the outside face of the bearing being worn OR the bore of the bearing holder?? Hope it doesn't give you problems down the road...er channel.

 

[Heron]

Greetings,
Mr. H. Hmmm...Hard to tell without removal of the cutlass bearing but is the movement due to the outside face of the bearing being worn OR the bore of the bearing holder??

Hard to tell actually....Now that the Bearing is secured there is NO movement so I think it will be fine. Water ingress through the Bearing to the shaft log seal (PSS in this case) is normal so it would seem not to matter too much as long as the bearing is securely held in place.. Movement before was not much but noticeable when wiggled and not enough to cause any vibration issues. It doesn't wiggle any longer and the bearing is pretty tight on the shaft which is to be expected I guess since there was no rotational wear going on between the bearing and the shaft. My bearing is essentially like new inside.... Peering through the Set-screw holes there did not appear to be any rotational wear evident on the brass shell of the cutlass bearing. I think I've caught it in time and it will be fine.

 

[RT Firefly]

 

[sdowney717]

"noticed side to side play.."

And now no play, what you need to do is recheck the engine-shaft alignment when back in the water. Feeling side to side play would mean enough movement to certainly be beyond .005 inches alignment at the coupler.

 

[bilge53]

Did you replace the bearing? Now is the time to get to stock specs.

 

[psneeld]

Spinning the cutlass doesn't mean that the engine is out of alignment...but now that cutless might be.


Tightening up the set screws may make it snug but it could be cocked off line. Without making up that spun out wear...might wear out cutlesses faster.


We had the spinning cutless problem with all of out Shamrock keel drives. Some got broken off and new stainless vee struts were constructed. Others due to the spinning cutless...we just cut off the glass keels with imbedded cutlesses and replaced with stainless vee struts with a much a better cutless set.

 

[sdowney717]

I am thinking the entire cutlass bushing is now lifted - pushed the entire lower shaft one way or the other, so not necessarily cocked. Which it would then cause the coupler to be out of alignment since the bottom of the shaft has moved over. There was enough play to be felt, which is a significant amount of play.

 

[psneeld]

in this case, you may never be able to align depending on where the cutless wound up...better to try to get it back in the original position.

 

[Heron]

Thanks for the comments all! Given me a few things to check. The bearing is positioned correctly in the log. The Log has 2 set-screws at the 2 and 8 o'clock position. I'll relax these and get the shaft to the point where it rotates easiest in the bearing. That will center it on the existing shaft alignment. It will somewhat self align in the 10 and 4 o'clock plane if there is any slop (Little if any) at the inside end of the bearing. I'll also review the cutaway drawings I have in my Owners manual. The shaft is pretty short overall and it does have a drive saver coupling installed. Alignment will be checked when back in the water. I'm sure it will be fine.