Strut & Shaft Alignment

you may have to shim your strut, if you do lift the shaft up to the trans coupling it will load the strut bearing, that is the first place to start is aligning the strut to the hole and then on up.

it looks like you will have to shim the aft bolts, normally when your done aligning you should be able to spin the rotating assembly with one finger

Pete, it looks like there are cracks towards the front of the strut

eric lavine wrote: it looks like you will have to shim the aft bolts, normally when your done aligning you should be able to spin the rotating assembly with one finger

Eric,
If the assembly can be rotated with one finger, can you assume that you're properly or that you may probably be aligned? For some reason, alignment is intimidating to me.

Sorry for the threadjack

Rob,
I took another look at the first picture and I need to take a step backwards here. Does the picture show the shaft all the way through the log? I'm thinking now it isn't? If true, then Eric's correct in saying that the aft two stut bolts need a SS washer between it's base and the hull. Give it a try, dry fit and report back.

Performed a dry fit with .070" thick washers (stern end of strut) in addition to the .070" thick rectangular shim plate that was already there for a total of .140" thick shim. You can see in the picture that I was able to get the shaft into the log, but it is riding and binding on the bottom; not even close to center. I'm beginning to think Pete is on to something regarding the possibility of having the wrong strut. How would I check this? To even get close to center, I think I'm gonna need at least another .250" shim, and I'm quite sure that's unacceptable. Two shims is probably pushing it. Suggestions?? I'm at a loss.

Rob,
Looking at the picture of the strut bolts in the bilge and not seeing any cracking there, I'd say all the cracking in the gel is just from stress. Since gel is hard and brittle, it doesn't take much to crack it. It's also common on a hull that needs a stringer job.

On the strut alignment, it looks like they had a issue with this one before considering the shim you found and it may have even been at the factoy. I've seen it before!! It's like the strut itself was mounted too far forward. You're past the point where shimming is recommended so I would suggest two options. Grinding the gel under the strut base as well as some of the base itself or moving the strut aft. Do you remember how much room was between the strut and the prop hub?

Rob,
Yes, I now feel you have the correct strut but, as mentioned feel the location is off. Anything past one shim with 5200 as a bedding compound and I'd be building up a new epoxy base for the strut. We just had a member do it. Besides milling some of the base, I feel you'll end up removing the gel at least towards the front. Get the strut where it needs to be even with some washer shims. Plastic wrap the strut base so the epoxy won't stick to it and grease the bolt holes. Then spread the thickened epoxy on the base and bolt it in place. When cured, you'll have a nice solid surface for the strut base.

The alternate is moving the strut location aft.

Rob,
I wouldn't worry if you needed a inch of epoxy! Just make sure it's filled with one of the high strength fillers.

Yes, you can leave the washers in. Use SS.

Kitchen stretch wrap. Yes, wax paper will work too. Grease your bolts and make sure the holes are solvent cleaned before the bedding.

Yes, you will bed the strut with 5200 just like you would without the epoxy.

Screw holes get the 5200 too.

I wouldn't go more than about .100 on the base and the reason I think you'll need to remove some gel.

BTW, I plan to use the 635 thin resin with aerosil-cabosil filler.

Robb - I borrowed a friends fixture to straighten this strut:

it wouldnt hurt to put a plate on the inside top to spread the bolt load for the strut, extra insurance i guess

DrCC wrote: DO NOT MOVE THE STRUT !!! Don't grind on it! It's a temporary fix. Right? Shim the strut, then shim the front motor mounts. You have a severe case of rotten stringer hull sag. Then, when you do your stringers, aline the hull with the un-shimmed strut. Cool boat!

Al,
Rob can't even get the shaft throught the hull hole and log without it binding.

Shim the front mounts only??? That will drop the ouput shaft at the trans and make it worse!! What about the aft mounts on the trans?

Whenever an old hull starts to sag,   the strut will no longer line-up without shims.
When you shim a strut, you must also shim the forward motor mounts.   Unless you have plenty of upward adjustment on the mounts.

A one more season temp fix.   Do not grind or drill holes,   shim away!

Don't molest your parts or hull just for one more season.

The rear mounts should be a common sense "given"

Adjust accordingly.

Meaning, you should still have enough adjustment.   If not, shim!

All very good points, and I really appreciate the insight. I'm taking it all in.

I've got a lot of work to do, so I'm taking one thing at a time. I will likely have to circle back on some of this when I'm ready, but at the moment, I am focused on getting the strut and shaft measured and straightened, if both are required. After making several phone calls, I have found a shop that has experience with doing both. It will likely be Monday before I can get the parts dropped off. This weekend will likely be dedicated to fitting, cutting, and sealing my temporary secondaries. My goal is to have this boat ready by Memorial Day!

If I'm lucky, I might also have a little time to hunt some morel mushrooms while the epoxy is setting up !!

I will definitely have more questions come this Fall as to how to fix the "hull sag" before I put new stringers in.

Can the hull be repaired? I see a lot of "lines" going across the width of the boat at regular intervals and continue for the entire length. Are these "flex" cracks in the gel beneath the paint due to waterlogged stringers? Is this costly to fix??