J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Removing or Replacing Stuck Shaft

Hey gang, I was getting my cutlass bearing replaced and asked the company to take a look at my shaft seal and coupler plate. The shaft seal needs replacing and the coupler plate appears to be permanently attached to the shaft by their estimation. Their suggestion is to cut the shaft for removal, replace the shaft seal, have a new shaft made, B.O.A.T.

He's gonna do some price checking for me for a dripless seal and a new shaft. I'm pretty handy, but it seems like I could easily spend a day trying to free the shaft with no results. Perhaps now's not a bad time to get a brand new shaft and seal...



I've lost the art of adding an image to a post, but it's in that link.

Thanks,
Blaine

I Had the same problem and spoke to a friend who is an engineer and he removed the gearbox and used an puller to separate the coupling and prop shaft with a bit of heat.

Seems you may be embarking on a rather expensive endeavor if you choose to cut the shaft. As you know it's stainless steel and won't be cheap to replace
I'll start with the old cliché - if it ain't broke, don't fix it.
What could be wrong with the shaft. Do you suspect it might be bent. Do you think you have an electrolysis problem between the propeller and the shaft
Aside from the above, there's not a whole lot that can go wrong with the shaft. It rides in a piece of rope at the stuffing box and a rubber/plastic bearing at the cutlass. It's doubtful the shaft is worn

My suggestion: disconnect the shaft from the engine at the coupling (mark it so you can bolt it back in the same rotation you took it apart).. Rotate the shaft by hand - if it rotates feely it probably isn't bent. Check the gap between the engine coupling and the shaft coupling. There shouldn't be more than a few thousands difference. Rotate the shaft - again the clearance should be within a few thousands as you rotate it. If there is a huge variation as you rotate the shaft, then the shaft is probably bent. If there is a difference in clearance but is the same as you rotate the shaft - you have an alignment problem between the engine and the shaft
Pull the prop. check the treads and check for electrolysis. If there is any electrolysis, it should be in the prop not the shaft When you are all done, replace the 4 coupling bolts with stainless steel bolts and SS nylock nuts

Oh I've got no problems with the shaft Russ, except that it needs to be removed so that we can replace the shaft seal.
Will find out shortly if it will budge at all, but it looks like that shaft wasn't even removed when the boat was repowered in 2006, so it doesn't look promising.

You should be able to replace the stuffing box seal (rope) from inside the boat with the shaft still in. Check out u-tube videos.
Some even claim you can replace the stuffing box seal with the boat in the water. Clean the treads and use some penetrating oil before attempting to back off the compression nut

If you want that shaft coupling off, first - if you can, separate it from the engine. For me, the coupler bolts were as much of a heart ache as getting the coupler off the shaft. Back out the two bolts that hold the coupler to the shaft. Again another fun task as the coupler is cast and the bolts are steel

Next go get some high end penetrating oil. (some buddies that own a machine shop gave me some. Don't know the brand but it was orange in color) Soak the coupler/shaft over night. Get something to insulate the shaft/coupler from the hull and then heat the f**k out of it with a propane torch. Get a 5 pound hammer and have at it - good luck

You could use a torch on the coupler to try and expand it, then a hammer. If that doesn't work, use an angle grinder to split the coupler. In any case, once all is apart, you have some cleanup to do. You may want to consider a new shaft side coupling anyway.

Another thing to try is unbolt from the transmission and slide shaft aft. Put socket smaller than shaft diameter in center, use longer fasteners on coupling and squeeze to see if it will push the shaft out.

I saw some pictures of his issue. His stern tube hose has signs of cracking along the edge of the hose clamps, so to replace that hose, the coupling flange really does need to come off.

The socket and 4 longer bolts trick is good as long as you don't have to put so much force that the flanges will distort. I saw a puller on youtube once which had something that looked like a 3/8" round plate with 4 holes in it, a socket (or similar) at the center of it which worked with two bars that each had two bolt hole (slots) and a half circle in the middle for the shaft to pass through. This allows the force to be applied to the aft end of the coupler instead of the flange. Unfortunately, I can't seem to find this video now.

Ask the mechanic if a dripless seal can be installed without removing the coupler plate. These seals can sometimes be installed over the existing shaft and coupler assembly, eliminating the need to replace the shaft altogether. While replacing the shaft seal with a dripless seal might seem doable, properly installing a dripless seal often requires specialized tools and knowledge. Assess your comfort level and the tools you have available before attempting this yourself.

Hi Blaine, I had almost the exact same problem last winter - my cutlass bearing was worn out and the shaft has to be pulled to to replace it. I hate to break it to you, but it is an absolute pain in the a** job, but it can be done. It took us three or four weeks of working on it every two days or so to get it off.

Step 1 - Prep - First thing I would do is to get as much of the support structure for the cockpit and other stuff out of the way, I smashed my hands and wrist on it a couple of times when the socket wrench slipped, and with the amount of force you have to use to get this thing to budge, it HURT.

Step 2 - Penetrating Oil Soak - Next I would do as other have suggested and soak the ever-loving piss out of it with Kroil (which I think is what Russ is referring too, works wonders) or SeaFoam penetrating oil, but I would start at least a week, if not several weeks in advance. Put an oil adsorbent pad underneath, soak thoroughly, rotate the next day, soak, repeat ad nauseum for as long as you can stand. Penetrating oil works, but with something as seized up as these bolts are, it can take a while. It felt like whoever put the prop-shaft back on the coupler used a hydraulic press on ours. You can also heat it gently with a hot air gun at the same time to help the oil soak in.

Step 3 - Removing the coupler bolts - I had a couple spare lifeline stanchions, and when cut down they make perfect extensions for a 1/2 inch socket wrench, you are going to need the extra leverage. If you don't have one, buy a spring-loaded automatic center punch like this one (https://www.homedepot.com/p/Husky-6-in-Automatic-Spring-Loaded-Center-Hole-Punch-70079H/302880581), file down the head so it is round or flat, and whack the bolt head a few times with it. The short, sharp impact helps to free up the bolt and it won't munge up the threads like hitting it with a hammer could. Grab your socket wrench with *six*-sided sockets (you need as much bearing surface as possible for this job) and go to town. You will need a second person to help with another wrench to brace the bolt closer to the engine with the largest Yanmar wrench against the engine pan to stop the coupler from spinning. It can be done with one person, but it is tedious and the 2nd wrench will slip a lot, I held it gently in place while apply pressure and eventually it will be forced into place and you can pull the wrench with both hands. Once you have all four bolts free the prop-shaft and the coupler should come free of the transmission at this point, if it doesn't, a few good whacks with a hammer should convince it to let go.

Step 4 - Pulling the coupler - Now comes the fun part, you need to build a press inside the engine compartment. Grab four grade 8 bolts and nuts that are the same as the coupler bolts but about an inch longer (yes, we had to make *a lot* of trips to the hardware store - I would buy many extra nuts, they get beat up) and a socket just smaller than the prop shaft. Insert the socket so that it pushes against the back of the tranmission and the prop shaft inside of the coupler but not the coupler itself, I used a pair of wide needle nose pliers to hold it in place while I placed the coupler/prop-shaft combo up against it. Now thread on your extra long bolts a tighten the whole contraption down, a second person comes in handy to hold the socket in place while you get it tight enough to stay still. Next, work your way around the coupler bracing the opposite bolt against the engine pan using the large Yanmar engine wrench - the pan can take the force, it is extra reinforced in the stern. Tighten the bolt so that it pushes the wrench holding the opposite bolt *down* into the engine pan, there is almost no way to hold it against the forces you need to apply to break it loose. Work your way around the coupler swapping in longer bolts and sockets as needed, and after much sweating, bleeding, cursing, wailing, and gnashing of teeth the coupler should eventually separate from the prop shaft. Heating the coupler helped as well, but you need to get it very hot, likely smoking hot to help, so wear gloves when warm.

Et voila - your prop-shaft should now be free, in four "easy" steps. I would recommend buying a split coupler and coating it with POR-15 rust-preventative paint so this doesn't have to happen again.

Yeah, we did one painful $1000 step back in 2021. After a basic torch and wrench effort on my part, and my boat partner not having time. We hired the local, well-respected pros.

They cut the shaft, removed it from boat, machined a new one, and replaced the coupler with new, and new shaft seal parts, which were the only parts that immediately needed replacement. Cutlass bearing got done while we were at it.

Interesting to see how someone works when they cost $180/hr. Guaranteed fix with 2 hours of work. Knowing the boat better now, I would be more comfortable separating the coupler and cutting it off the shaft to save $500. Sometimes I have more time than money, so the math is always changing.

Also the professional marine advice was that they did not recommend a dripless on a 3/4" shaft, so I took their advice and refreshed our existing shaft seal.