Strut/Shaftline Alignment

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Garry Elmer

I am geting ready to align my strut and shaft line. The strut on our 1980 H33 was out of alignment and when a new cutlass bearing was installed it bound the shaft up in the strut because it was off several degrees in the vertical. I have a DELRON insert with the OD of the stern tube and ID of 1 inch for the shaft. With the stuffing tube assembly removed this insert should hold the shaft in the axis of the stern tube and I'll re-mount the strut to the shaft. Once in the water I can make minor changes with the stuffing tube and align the diesel flanges. I have heard several great ideas for bedding the strut last time I posted about this. Each of these ideas was based on a "hard" mount. When I dropped the strut I found a 3/16 sheet of rubber between the hull and the strut. ?????? Ideas? Thanks! Garry Elmer Mystic, CT http://www.99main.com/~elmergw/
 
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R.W.Landau

A Gary Question.

Was the rubber used as a shim? My thought is to reconnect the stuffing box, with shaft disconnected from the engine. Connect the strut again. That rubber may be a good thing. If a line is dropped overboard, a prop has enough power to wrap that line around itself with force enough to pull a shaft sideways through a full keel. The rubber would act as an air bag, reducing the inpact by a milli second decelerating the initial force. Volvo does a good job of this in their crash designing. The rubber may be a good thing to leave in. Once you have aligned the strut to the stuffing box, align the engine. Don't rely on the give of the rubber at the strut nor the flex connection at the stuffing box. The cyclic loading with soon wear them out. Just an Opinion r.w.landau
 
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R.W.Landau

Garry , you have a good idea

It took me a day to realize what you said. That delron sounds good. I would disconnect the shaft from the transmission. Leave the stuffing box disconnected, and loosely install the strut. Slide in the Delron then check to make sure it is centered inside the tube and at the exit. Tighten the strut, and pull the Delron to the inside. This will allow you to go back out and check the shaft where it exits the tube. Give the shaft a little spin to make sure there is no bend in the shaft from the strut to the inside of the tube. Make the alignment with the engine mounts while the delron is still on the shaft.Once it is aligned, tighten the bolts, pull the delron out and your shaft should be centered in the tube. Replace the stuffing box. Once in the water all you should have is minor adjustments to the alignment of the motor mounts. good luck r.w.landau
 
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Sam Lust

Getting the shaft (straight)

As you might recall, I'm in the same situation (notice I didn't say boat?) as you as some idiot allowed my Stayset X halyard to get wrapped up in the prop, bending my strut. I,m a bit leery about the idea of seating the strut in rubber. I'm concerned the flex would induce vibration and eventualy allow water leakage. My strut was seated in some sort of hard compound, probably filled polyester. The adhesion was mediocre and once I got the bent screws out it broke away easily. I'm figuring on bedding mine into polyester filler, Marine-Tex, or filled epoxy resin; depending on my mood when I get around to doing it. Any information anyone has here would be appreciated. The idea of the Delrin bushing is excelent, assuming it was easy to come up with. I've been figuring on lightly supporting the strut while centering the shaft in the stern tube with tapered wedges tapped lightly into place. If you want to send that centering bushing along after you're done I'll gladly borrow it even though it wasn't my idea! One note: before you go anywhere, spin your shaft on a set of "V" blocks to make sure it's true. As a guess I would think the shaft should be within .003". As far as alignment, mine changed less than .001" from when I set my 3GM30 in place with the boat on land to the end of the season when I checked alignment in the water. Contact me directly and we can compare notes in greater detail. samlust@monmouth.com
 
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Terry arnold

strut alignment

Since after all the purpose of the strut is to support and keep in alignment the prop shaft, seems that the base of the strut should be rigid. There was no rubber under my strut when I took it off in replacing the cutlass bearing. The West site, (www.westsystem.com) has the user manual on line which includes a fine discussion of using thickened epoxy to make a base for hardware.
 
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Terry arnold

strut alignment

Since after all the purpose of the strut is to support and keep in alignment the prop shaft, seems that the base of the strut should be rigid. There was no rubber under my strut when I took it off in replacing the cutlass bearing. The West site, (www.westsystem.com) has the user manual on line which includes a fine discussion of using thickened epoxy to make a base for hardware.
 
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Garry Elmer

Getting ready

Well, we're getting ready to fit everything up. I must be honest I was going to cut the delron off until RW Landau told me I could pull it out through the removed stuffing box! (Thanks RW!!!) The material under the strut may not be rubber. I am not sure what it is but I am going to go with a hard mount. Fit everything up and adjust the screws holding the strut until we get the right fit. If I put saran wrap over the mating surfaces whatever I inject in the void will come out solid and should be a workable shim. Clean the shim up and a thin coat of 5200 may do the trick. I am not sure yet. I will let everyone know! Thanks for all the input! Garry
 
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R.W.Landau

anxiously awaiting

your results. Garry, A few additional ideas. Could you hang the strut from the bolts until you get it lined up. Measure the shim required, loosen the strut and fill with a puttylike epoxy then return the bolts to the proper place. If you make a marker tracing around the strut this may help align it the second go around. If you do the saran wrap thing, grease the bolts so that they can be removed. r.w.landau
 
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Ken Palmer

Take pictures!

Pictures are worth a thousand words. If you don't have a digital camera, use a film type. I could scan the photos for you and publish them here on HOW. Ken Palmer, S/V Liberty
 
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Ernie

How did you get the bolts out?

I took off the nuts and managed to get the washers off but I cannot get the bolts out! The Phillips driver is useless. I locked two nuts on the top and torqued 'till I thought they would break with no luck. I beat them with a hammer. Pushed and pulled with a car jack with no luck. They are "glued" in with the same "hard white filler" that the strut is bedded in and refuse to move. I would love to know what magic is required to get them out. Ernie S/V Cindy Lou
 
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R.W.Landau

Impact driver

Ernie, Sometimes an impact drive will work on this kind of thing if it's not to chewed-up. I am talking about one you hit with a hammer not a pneumatic. I believe the white stuff is epoxy. r.w.landau
 
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Tim Schaaf

What is inside?

When I went through all this, I found that there were some hairline fractures on the glass inside the hull. After a fair bit of grinding, I reglassed much more thickly than the original. I also removed the wood backing block and replaced it with an aluminum one, with plenty of 5200, in and out.The whole thing is really strong, now. Don't ask what I did to beef up the rudder installation, which was also suspect! By the way, you should not have to remove the strut to remove the cutless bearing. Since my problems, like Sam's, were caused by an idiot catching a line in the prop, I added Spurs weedcutters. Now, I can chew up all the line I like, without hurting anything but the line! Actually, since a large number of boating disasters have, as a key element, a fouled prop, I do think they are a significant safety item. And, I do agree that the rubber must go!
 
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Garry Elmer

Strut bolt removal

I guess I was lucky. After reomving the backing nuts I rocked the strut side to side gently and it slowly freed things up. The strut came down with the bolts. The bolt heads were bent and they took some doing to get out but I did that on a bench. Garry
 
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