Replacing Shaft Coupler Bolts?

[Squidward]

Been making arrangements to have the boat hauled for PSS bellows replacement, which will involve uncoupling the shafts. That being the hardest part of the job, from what I gather.

It just occurred to me, what if I pre-break the coupler bolts, one at a time, and replace them with new ones? Leaving the actual coupler in place until the day of the haulout.

Seems like worst case scenario there'd be less work for the mechanic I planned on hiring, and in the best case scenario I might not need the mechanic at all.

Is there any reason not to do this? Been reading about the delicate tolerances on the flanges and whatnot. These are bronze split-style couplers. 4 inch flange if I recall.

 

[jimdavi]

My opinion is to just let the yard do the work you are paying them for. Good yards do this job all the time. New hardware is a great idea.

 

[SIBERNUT]

And the final touch would be buying bolts/nuts drilled for safety wire. Prob overkill, but what the heck. In for a penny......

 

[Comodave]

If you do them one at a time I don’t see any problems. I would spray some PB Blaster on the bolts a few days before to help break any corrosion. Do you have a 1/2” impact driver? If so that would probably break the bolts loose. The likely problem will be getting the coupler off the prop shaft. I made a piece of steel to help press it off the shafts on our last boat. With the socket in the middle as you tighten the bolts it presses the shaft out of the coupler. Just alternate the thighting and with a driver it will come right off.

 

[psneeld]

With a split coupler, wedges or chisels opening the splits should let the coupler slide right off.

 

[Comodave]

Split couplers are easy. But if you don’t have split couplers then it can be a PITA to get the couplers off.

 

[psneeld]

Split couplers are easy. But if you don’t have split couplers then it can be a PITA to get the couplers off.

First post mentionrd split couplers.

Using presses can deform a coupler, the advice I got and give, if you need to use a lot of press pressure, just toss the coupler and buy split replacement couplers. Either way it is also suggested a machine shop true the old or new couplers to the shaft.

 

[Comodave]

I missed the split coupler part of his post.

 

[jgwinks]

The bolts holding the shaft flange to the trans flange are usually fine thread. If you replace them they'll probably be coarse thread. I have no idea if that matters. I've never heard of those being hard to remove so doing it yourself won't save you anything. The split coupler is a different matter. Most split couplers still have a press fit section and getting that apart can be difficult. Pulling the bolts out is easy, so you still don't save anything. Just let the tech do it, he'll probably charge you for it anyway.

 

[STB]

I wouldn't bet on those bolts being a problem. There is no reason they should be. They might get some moisture or solt water, but don't get super hot.

In the worst case, if one breaks at the yard, they are set up to drill it quickly. That might be a project for you, depending upon how often you do it.

I'd just let the yard do it. You doing it won't wave you significant money or time. I suspect.

 

[Squidward]

Thanks for all the input. Sounds like there's no benefit to starting early, although I applied some PB Blaster to the bolts today with a q-tip. May do it a few times between now and the haulout.

 

[boomerang]

With a split coupler, wedges or chisels opening the splits should let the coupler slide right off.

Speak of the devil. Here's my project for this seasons haul out. If only the cutlass bearing would come out as readily as the shaft came out of the coupler!
Fun times! Not. Ahhh...the joys of boat ownership and being a do it yourselfer.