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strut alignment

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bobct

Advanced Contributor
I had both my shafts aligned last year when I replaced my Stb cutless bearing and both shaft logs. The alignment was off on both sides for years. On the port side after the alignment, the shaft rode on a different part of the cutless bearing and was harder to rotate when pulling the prop. No vibration though.

This year, I removed the strut to re-bed it and also get the cutless bearing changed. The place that installed the new cutless bearing said my strut was very slightly bent which they corrected. Which direction, I don't know.

I reinstalled the strut and there's a slightly (tiny) larger gap on one side but I can turn the shaft without the props installed - it's like butter. There's no play if I try and move the shaft around.

*Should I install the strut as is and try and close the gap with another shaft engine alignment on the hard?

*Try and align the strut and leave the engine alignment as is?

*Do nothing and check the engine alignment in the water. Obviously, I can't see the shaft/cutless bearing relationship at that point.

thanks,
Bob
 
If the gap you talk about is in the cutlass bearing....it's worn, replace it. It should be even, without spaces. Then see if it still spins nice by hand, if not, re-align. HTH
 
just to clarify, the gap is in the cutless bearing/shaft but it is brand new. I had a similar gap on the old one AFTER the correct alignment but that greatly increased the effort needed to spin the prop. The gap now (with new cutless) and strut dry fitted is about the same but virtually no effort to spin the shaft.
 
As I'm sure you know, you must align the engine and shaft with the boat in the water. The strut and cutless bearing should be as close in alignment as you can get with the boat on the hard, which will give the proper engine alignment when the boat is back in the water. So your short answer is align strut and shaft, then align engine.
 
Bob:

I've be inclined to measure the shaft to make sure it isn't worn in the area where the gap is before doing anything. If the shaft is not worn and rotates freely then I'd verify the shaft sits centered in the log. If that is fine, I'd leave the strut where it is and verify the engine-coupling alignment after you launch.

If you decide to shim the strut, go slow and proceed methodically. Due to the way most hulls are produced, it may not be possible to get things 'perfect' but still have a functional drive line.
 
bobct said:
just to clarify, the gap is in the cutless bearing/shaft but it is brand new. I had a similar gap on the old one AFTER the correct alignment but that greatly increased the effort needed to spin the prop. The gap now (with new cutless) and strut dry fitted is about the same but virtually no effort to spin the shaft.
Click to expand...

Easy of turning says a lot. It can't be too far out with a new bearing and still turn easy. Given the PIA with struts on/off, i'd not mess with it. The shaft COULD be worn, but if there is not sig. play, leave it alone.
 
ok, thanks guys. The shaft is pretty close to centered in the shaft log. This side was almost bottomed out on the shaft log last year before the alignment so I remember where it WAS.

I thought that being able to rotate it without the prop installed was a good sign as well. I'll check the shaft, I didn't even think of it being worn as an answer to what I'm seeing. There is zero play but I'll doublecheck it, probably leave it alone and then check the alignment in the water.
 
Hey Bob,

Just to pile on.... A few years back out shafts were so badly aligned in the drive line that they wore away one side of the shaft log clear thru... a major leak did not occur ..BUT I AM SURPRISED....FYI
 
Al, I remember you posting that. It's amazing how out of touch boaters can be on the mechanical workings of their boat. When I boat mine, the previous owner let the packing go so long that the bilge pump came on every ten minutes AND the other pump was burned out! Was probably like that for years.
 
Does the fact that it is hard to turn the prop by hand mean that something is out of alignment in every case? I have always had the ability to easily spin the port prop by hand but it was harder (alot) to turn the stb prop, both in and out of the water. I wondered if the strut was out of alignment and have examined the cutlass bearing for uneven wear (mine are 10 years old). There is no uneven gap in the bearing. Two seasons ago after a grounding resulted in new props, my mechanic convinced me that my stb shaft MUST be bent because there was "wobbling" of the transmission when the shaft rotated. So, pulled the boat, the shaft was pulled and dialed, no bent shaft was found, I was then told it was the front engine mounts that needed to be replaced to be able to lift the front of the engine up to align the shaft in the center of the log. I figured after all of that it would result in the stb shaft turning as easy as the port... nope no deal. I have no unusual vibration or noise, especially since I got the new props. So, is something messed up, or is that just the way the prop turns, so to speak?
 
Scott; have you turned the output flange of the transmission by itself? There is a bearing preload, could cause a difference between sides.
also: Do you see this "wobble" on either shaft at dead slow speeds?
 
No I have not turned the flange by itself, the "wobble" I only saw when the boat was tied to the slip and put in forward gear, at idle obviously. no wobble on port side.. When you say a "preload" is it possible that one tranny may have a different preload, given they are both same manufacture etc... ? The port side is the easy side to turn and that is the one that I understand has to have the "reversing" dohicky, to get the prop to spin the right way, sorry do not know correct term. they are Velvet drives...
 
I too have a left hand and right hand rotation Velvet drive transmissions. Both couplers feel about the same when turning by hand. I'm not sure that's always the case but just a point of reference.

Bob
 
Sounds like the 5000 series, not the 72's. Either way, the output bearing preload should have been the same (within the spec'ed tolerance) when it left the factory.

In a desirable world, both shafts should turn with a similar amount of reistance. Things wear differently, from side to side, and given the accumulated time, so difference would not be abnormal. I'd still be inclined to check it out and fix it now, if needed.
 
Yep, they are the 5000 series. What else should be checked? The boat was hauled, the shaft was pulled out of the boat and "dialed", the mechanic said that the shaft was not centered in the log but it was straight, his diagnosis was that the front motor mounts were "stripped" (they are the standard crusader mounts) so he replaced them and said that by raising the engine up in the front he was able to get the shaft in the center and align everything up. I have no unusual vibration when running, just have a hard to turn prop (in relationship to the port side)... what else could it be? Cutlass bearing looks ok, shaft tight in the bearing, no gaps on either side. He never said anything about how the strut aligned up, but would (should) a misaligned strut show up by looking at the cutlass bearing and how the shaft sits in that?
 
Well, there are only 5 possibilities that I can imagine. Misalignment in the cutlass, paint on the shaft in the cutlass area, overtightened log, rubbing a side of the log, transmission output shaft bearing preload. Most of these can be found by disconnecting the two flanges and manually turning the shaft in various positions, in addition to turning the tranny flange solo.
 
Visual inspection of the cutlass doesn't always reveal a misalignment, especially with the 'longer' bearings. Concur with DD's list on the rest of the places to check. The larger the shaft size, the narrower the window for the engine end of the shaft's position is, for correct alignment. Also, us small guy find it a bear to hold the larger shafts in a fixed position to assess the cutless-log aspects.

One other area that can cause grief and is real hard to inspect - the internal condition of the Crusader motor mounts. If you've accumulated thousands of hours (over 3000), I'd almost guarantee you that they are most likely broken inside. I don't know where the window (for their expected failure) starts but I'd suspect 1500 hours would be a good place to budget for new mounts. A broken mount will not maintain alignment and will drive you nuts if you try.
 
You could try using a hard Maitex type of shaft bearing, made as a clearance fit in the carrier/strut. Have a dry run assembly and with the shaft chocked you should be able to slide the bearing in by hand on the shaft and it should easily rotate. That shows the strut is aligned, then coat bearing and strut in epoxy slide bearing in and you know it is aligned.

The clearance for bearings should be available from the manufacturer and this can be measured, maritex provide a clearance chart that gives a break down of the running clearance and a guide as to when it should be replaced. these have been lasting up to three times as long as rubber bearings.
 
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