skeg bent

[charles kaufman]

I am having my cutlass bearing replaced but the yard doing the work says the strutt ( skeg ? ) that holds the bearing is not straight and will not allow the shaft to line up,it is a forward -aft problem not. port starbord. The yard wants to go in and remove the glass around the out side of the strutt so they can get it loosened up to shim ? This is all new to me. Any ideas on fixing this ? And I wonder how it got this way since it is in a well protected spot, maybe it has always been that way from manufacture ? Thanks all.

[Ray & Sandy Erps]

Geez,

That sounds expensive.  I've learned to be a little skeptical when it comes to diagnostics given by repairmen.  If the shaft can't be lined up, how was it aligned before they took it apart?  Take a look at the old cutlass bearing.  If there was an alignment problem the old bearing is going to show uneven wear, that is wear on one side foreward and wear on the opposite side aft.  If it doesn't show this uneven wear on the old bearing I'd start asking more questions before committing to some sort of a repair.  

I just had my cutlass bearing replaced last month.  I've done it before on my previous boat but asked the yard to do it this last time, figuring they had a special tool to press it out.  The guy who did it, used a big hammer and a drift.  I was a little ticked.  If your strut is bent and the cutlass isn't worn, I'd suspect that the boatyard bent with their big hammer.

[Michael Algase]

I don't think the problem is a strut that is bent fore and aft.  Given the section size in that direction, you'd have to hit something pretty hard to do that!  there is another possibility as to why it appears this way.  Not sure how to describe this, but I'll try.

I noticed this spring that although the shaft was centered in the aft end of the strut, at the front end, it was closer to the bottom of the strut opening than the top.  When I looked at where the shaft passes through the shaft log into the hull, I noticed it was biased toward the bottom of the shaft log as well.

The conclusion I drew was that the engine was a little too low, because if you raise the inboard end of the shaft, it helps align both these locations.

I raised the engine about one full turn of the adjustments on the aft mounts, then the same amount, plus about one additional facet on the adjustment nut.  If you want to raise the engine, assume it pivots at the strut.  Since the aft end is closer to the strut than the front (shorter radius to the pivot point), the forward end being further away must move more if the shaft and engine are to stay in alignment.

Anyhow, after the adjustment, I was able to realign the shaft flange to transmission flange to within a couple of thousandths again (got pretty lucky on the guess at how much more to raise the front than the back).

Bad news is that it didn't help the vibrations, but when I had the same vibrations in neutral that I have in gear, I figured the issue is motor mounts.  Guess what next spring's project is . . .

Just a thought.  I'd be curious what measurements / symptoms would indicate to the yard the strut is actually bent.  A whole lot easier to adjust the engine an eighth of an inch and realign than to loosen, shim, and re-bed the strut.  Same theory applies up or down as long as there is room in the shaft log.

V/R,
Michael

[SteveLyle]

It's been fairly well documented that the early C34's had the engine set too low relative to the log, which puts the shaft low in the log even when at the top of the engine mount adjustment.  A comon fix is to add 1/2" to 3/4" blocks under the motor mounts to lift the engine.  This has reportedly solved several mysterious "hull vibration when motoring" problems.

At some point Catalina appears to have solved the problem themselves, either by modifying the shaft log, or raising the engine bed - not sure which, but I'd guess the former.

[Ron Hill]

Chuck : You didn't give the year/hull # of your boat !

The shag is what the strut is mounted to.  To bend (fore & aft) the strut is highly Unlikely as the rudder protects it from the rear and the keel from the front.  A dead give-a-way is if the gel coat around the strut is or is NOT cracked!  Inspect your's and you make the decision.  Another point is that if you are on jack stands (which I suspect), the hull is warped out of shape and it's natural that the shaft in the cutless isn't perfect.

As Steve and a few other have mentioned, you engine is probably too low.
 
MUCH easier to move the engine than remove and rebed the strut.
Again, remember that you can only get shaft/engine alignment when the boat's in the water (for more than 24hrs) so the hull gets back into shape.  The rigging also needs to in tune.  

A few thoughts.