Shaft coupling is a rusty lump, how to remove

[tenders]

So you can see why cutting those bolts off opens up the whole new problem of getting the engine coupler off so you can drill out the remains. It might have been worth it.

I haven't had to take that nut off on my boat (and I think the arrangement is slightly different on my V-drive). I would suggest trying to clamp the flywheel in place with a clamp or a Vise-Grip, locking it where you have some leverage on a big gear while you whale away on this little gear with your big wrench.

"Is that nut reverse threaded?" certainly is a very important question at this stage. I don't know the answer. Does the Moyer manual mention this? I don't have my copy handy.

(Also: is the shaft salvageable now that it has that cut in it across the keyway? I would say yes, for the way I use my engine, but some might feel otherwise.)

[JimF]

My intention was to replace the output coupling rather than drill out the bolts.
This my desire to remove it. I think the shaft will be fine, the cut is all the way around but the real "grab" area is past where the cut is, and the cut is a tiny fraction of the total surface.

[Tim]

You will need to hold the output coupling with a large pipe wrench while attempting to remove the nut. Remember to straighten the tabs on the retaining washer first. The nut is very difficult to remove. I had to attach a 3 foot section of pipe to the end of my wrench to get enough leverage to break it free.

[Al Schober]

You can remove that nut just by drilling into it. Whether you drill on a radius or parallel to centerline, try to stay away from the threads in the transmission tailshaft. Two holes 180 apart will weaken the nut enough that it can be split with a chisel. Add a new nut and lock washer to your shopping list. While you're in there, also replace the seal.

[ndutton]

Why work so hard??

http://www.moyermarineforum.com/forums/showpost.php?p=76789&postcount=3

[sastanley]

Ah, Jim F...now we are getting to where I can contribute. I tried a pipe wrench on the coupler flange, while I used a 4' pipe on my breaker bar. No good.

The impact wrench will likely solve the problem as Neil suggested. It took me longer to muscle the air compressor into the Jeep and get it out and run the extension cord than it did to break it loose...after wasting the entire afternoon before with aforementioned breaker bar.

There is a locking washer...notice the tab(s) that are bent over onto the nut flat. Bend those back vertical again, and put an impact wrench on that bad boy if you can, and it will come off.

I can't believe the thread below is 5 years old, but it is...start here and power thru the last couple pages real quick..the link I am giving you is exactly where you are right now.

I ended up replacing everything from the rear main seal back..but my seal was leaking anyway, so when I had shaft log damage to repair I yanked it all.

http://www.moyermarine.com/forums/showthread.php?t=4044&page=12

[JimF]

A new dilemma

So as I understand it, its pretty tough to get the nut holding the output coupler on. off I don't have access to an impact wrench, and I don't have much room to use extra leverage like a breaker bar. Though just cutting it in two places and splitting it off seems like it might be the play. However, after reading the thread that sastanley recommended, it seems like once I have the nut off, I still have a big job ahead of me to get the coupler off the tail shaft anyway, and I would need to be able to use the 3 holes that currently have cut off bolts in them to screw in long bolts to apply pressure to break it out.
SO it seems like it is worth drilling out the three bolts in place first, and if I can get them out without much damage to the threading in the holes, go ahead and re-use the old output coupler and not replace it. If I do this I won't have an opportunity to replace the seal behind it, but it isn't an issue right now. I do expect to have to get the beast out of the boat for an overhaul sometime in the next few years, last overhaul was in 1989. It was 16 years to its first overhaul and its now been 26 years, Though you never know, its running just fine and while I use the boat about 50 days(short Maine season), the motor only sees 30 to 40 hours of use a year. Even on a 5 day cruise this year I only had it on about 8 hours total.

So I think my next step should be to drill out those holes

[Dave Neptune]

Jim, if it runs good what is the point of rebuilding? My engine is going on 45 years of uninterrupted service, IE it's original except for one exhaust valve which was replaced in 1983. Since then I have put on at least 200 hours a year and I have no idea before 1983 other than it did "bash" back once from Cabo before I had her.

Dave Neptune

[JimF]

Rebuilding

Right Dave, I have no intention of pulling the motor just for the hell of it, I just feel like someday the salt will finally take its toll.

Until I will just keep going, motor starts first time every time and purrs.
Someday it may not, if it ever does it's coming out because I already know of a few issues where things are getting dicey, manifold studs, water jacket bolt holes, if these things are going, how long until something more important goes? I love the motor but I dream of a new Moyer short block, and not worrying.

[sastanley]

So, Jim..if you decide to drill out the old broken bolts...be careful to start small and slowly work up in size..then before you get into the threads in the coupling, hopefully you can use a pick of some sort to peel out the remaining pieces of bolt in the threads and be good to go!

I would also suggest a run thru with a tap to be sure they are clean.

[BadaBing]

A few years back I needed to drill out alot of screws for a glass and aluminum railing. To cut down the workload I ordered several left handed bits. They cut in in a counterclockwise rotation.
The advantage being that the heat and torque of drilling, stepping up through s everial bit sizes, caused many of the bolts to loosen un enough during the drilling process that some of them did not require an easy out and those that did came out much easier.

Now, when needing to drill out a bolt, I make a poi t of us I g the reverse twist bits for my first few steps.
And let not forget generous amounts od on blaster.

[JimF]

Job done! Thanks for all the advice -

Two of the cut off bolts came out nicely with an easy-out after being drilled all the way through. The third would not come, and I had to keep stepping up in drill bit size and tried several different easy-out varieties until I got alarmingly close to the threads. This is where a left handed drill bit would have come in handy (which I could not find any where, and will now order online (who has them?).
The remains of the screw eventually spun with the drill out the back of the coupler hole and had to be serially turned and cut off (several steps until I could get the entire carcass of the bolt out. There is not much room behind the coupler and the whole bolt could not come out, so it had to be spun a few threads, cut from behind then spun some more and cut some more. All the while contorted like a pretzel down in the bilge. But I did get the whole thing out and was able to thread in a new bolts in all three holes so no issues with the threads in the old output coupler. The boat is now tucked away for the winter, shaft, re-packed stuffing box and new cutlass bearing will be re-installed next spring.

[hanleyclifford]

Two of the cut off bolts came out nicely with an easy-out after being drilled all the way through. The third would not come, and I had to keep stepping up in drill bit size and tried several different easy-out varieties until I got alarmingly close to the threads. This is where a left handed drill bit would have come in handy (which I could not find any where, and will now order online (who has them?).
The remains of the screw eventually spun with the drill out the back of the coupler hole and had to be serially turned and cut off (several steps until I could get the entire carcass of the bolt out. There is not much room behind the coupler and the whole bolt could not come out, so it had to be spun a few threads, cut from behind then spun some more and cut some more. All the while contorted like a pretzel down in the bilge. But I did get the whole thing out and was able to thread in a new bolts in all three holes so no issues with the threads in the old output coupler. The boat is now tucked away for the winter, shaft, re-packed stuffing box and new cutlass bearing will be re-installed next spring.

Good work. Couple of loose ends: make sure you clean and oil the surface of the output coupling and it wouldn't hurt to match the new shaft coupling up to it for a trial fit to make sure all is set. Check for distortions since you have been working around it. Also, have you planned your new set up so as to give you more room to slide the shaft aft and have better access?

[JimF]

new stuffing box

I did get a new stuffing box assembly. the metal parts are about an inch shorter and I can cut the hose down to gain another inch as well, so I should end up with about two extra inches which I hope will be enough.

I did not attempt to mate up the new shaft coupler with the output side but I did soak the coupler real good with Sili Kroil before I covered the boat for the winter. The boat is now hibernating in Maine (I live in Conn) for the winter, further work will have to wait until spring.

[hanleyclifford]

I did get a new stuffing box assembly. the metal parts are about an inch shorter and I can cut the hose down to gain another inch as well, so I should end up with about two extra inches which I hope will be enough.

I did not attempt to mate up the new shaft coupler with the output side but I did soak the coupler real good with Sili Kroil before I covered the boat for the winter. The boat is now hibernating in Maine (I live in Conn) for the winter, further work will have to wait until spring.

Nice. I hope you will continue this very interesting thread in the spring.