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Redbeard33 · 14-12-2010, 18:42

in the process of pulling out my yanmar 2qm15 from a hunter 33, everything was progressing nicely (well still slow cramped and greasy) but when the shaft-tranmission coupling was "attacked" it failed to even budge, i removed the entire bulkhead on the port side of the engine to gain more "purchase" still nada, with all the usual tricks tried (penetrant, heat, tapping, etc) my brother brought his grinder and we cut the head off one of the bolts and tried tapping it all the way through.....NOTHING so my question is has anybody had this problem and how did you solve it? the stuffing box will be replaced anyway so is it feasible (without spending a TON) to plan on cutting and replacing the whole shaft?!? my brother (a landbased gearhead) told me this would be his plan of attack if it was truck related but with everything marine costing more than if it were gold plated what is the reality?

Redbeard33 · 14-12-2010, 18:48

sorry I meant to include this picture with the original post.....

delmarrey · 14-12-2010, 18:54

If the coupler is really rusty, getting it off would damage it any way. So might as well cut it off by grinding a slot down opposite sides almost to the shaft and then put in a chisel and split the coupler. The rest you can get later. What remains on the shaft can be split also.

If the shaft is worn or bent you can just cut the shaft behind the coupler. Then buy a new shaft.

BTW if that's a 1" shaft I have a new yanmar coupler in my garage I'll sell at half price.I have some extra shafts too.

And some stuffing boxes........http://www.cruisersforum.com/forums/...ngs-49285.html

SailFastTri · 14-12-2010, 19:42

delmarrey has it right. on a prior boat I had the same situation, but we pulled the engine for other reasons so we were able to pull the shaft out from inside, with coupling still attached. We used a hydraulic press to push out the coupling, and it took 12 tons of pressure to free it even though it had been doused with PB Blaster a few days before!

Remove it as delmarrey wrote. Then take your shaft to a real prop shop that has equipment/expertise to measure if it is true and can be straightened. If you buy a second-hand shaft from delmarrey or anyone else, have it checked for "true" anyway, as it can be bent in shipment by poor freight handling. It shouldn't cost a lot and is worth the investment -- too much labor involved to chase vibration issues.

SailFastTri · 14-12-2010, 19:50

Quote:

Originally Posted by Redbeard33

sorry I meant to include this picture with the original post.....

That bilge looks like it was flooded for quite a while. IMHO you might consider pulling the engine and have it gone-over by a good mechanic, and while it's out you can wash that engine bay and paint it.

Evaluate and replace those old thru-hulls and hoses also, if needed. They look pretty sorry in your photo.

Redbeard33 · 14-12-2010, 20:08

thanks for the responses, delmarrey how much would you want for a coupling/shaft/stuffing box combo deal? if i can afford those (plus shipping) I like the idea of getting the whole "drivetrain" a facelift, however this must mean replacing the hull bearing as well?? and yes the engine bay has had some water in it for some time due to the old stuffing box I am pulling the engine now and cleaning the engine bay and towing to a yard to pull and replace ALL through hulls and seacocks in the spring nice eye though apprecciate the heads up, this boat is new to me and its going to take some time to make up for a few years of neglect

**capngeo** · 14-12-2010, 20:46

I misunderstand you intention..... Do you want to separate the coupling, so you can remove the engine, or do you want the coupling off the shaft?

Assuming the former, are you having difficulty removing the bolts?

Redbeard33 · 14-12-2010, 20:52

the goal originally was to seperate the coupling to remove the engine now, in the spring replace the stuffing box.....but yes i cant remove the bolts and the 2 plates are seized, the later talk was of replacing the coupling and shaft as well due to damage that would occur breaking the union

SailFastTri · 14-12-2010, 21:00

You should also have the new coupling "faced" by the same shop that trues the shaft. If the shaft or coupling is out of true by any more than a 2 one-thousandths you might have vibration problems. What they do is mount the new coupling on the shaft and turn it on the metal lath so the face that mates with your engine is true. Generally they're out quite a bit as they come from the factory... Makes engine alignment an exercise in chasing your tail.

SailFastTri · 14-12-2010, 21:03

Quote:

Originally Posted by Redbeard33

the goal originally was to seperate the coupling to remove the engine now, in the spring replace the stuffing box.....but yes i cant remove the bolts and the 2 plates are seized, the later talk was of replacing the coupling and shaft as well due to damage that would occur breaking the union

Watch your engine facing also (that mates with the coupling). If you hammer on it even once -- You might want to have your mechanic remove that piece so it can be machined true.

SailFastTri · 14-12-2010, 21:07

Quote:

Originally Posted by SailFastTri

Watch your engine facing also (that mates with the coupling). If you hammer on it even once -- You might want to have your mechanic remove that piece so it can be machined true.

Sorry to reply to my own post -- but further thought is that you're probably going to want to replace the transmission seals anyway. Ask your mechanic.

"While it's out, we should....." is a slippery slope

**capngeo** · 14-12-2010, 21:22

Quote:

Originally Posted by Redbeard33

the goal originally was to seperate the coupling to remove the engine now, in the spring replace the stuffing box.....but yes i cant remove the bolts and the 2 plates are seized, the later talk was of replacing the coupling and shaft as well due to damage that would occur breaking the union

IF the bolts are seized, before you start cutting, try TIGHTENING them. Sometimes they will snap off saving a lot of time, sometimes it will actually move a slight bit, and you can then loosen, and most rarely, some goober used left hand threads! If all efforts at conventional removal fail, you are on track with grinding off the head(s)... yes sometimes you need to grind off both for clearance. Get old Rosebud (Oxy-Acetylene Torch) out... propane plumber torches won't do! Heat only the cut off bolt in the flange and punch/hammer it out while CHERRY RED.

If the motor runs, try running it after the bolts are out and see if it breaks the coupling loose.... ONLY use forward, as reverse could pull the prop back into your rudder. If that doesn't work, use Rosebud to heat the driven side as much as possible, then let cool... try again to separate. I have yet to see one that will not part after heating... again, a propane torch won't do!

A trick for removing the shaft side from the shaft is to put a nut of a diameter smaller than the shaft, on the shaft end at the coupler face, then re-bolt the coupler to the engine (with longer bolts) tighten bolts as much as you can and apply heat to the coupling. As the shaft moves, add more nuts.

If all else fails you will need to cut it off.... but in 30 years, I've only done that 2 or 3 times. BTW..... look close for a pin the the hub/shaft. Not common on sail boats, but I have seen it!

Use common sense when using Rosebud in a bilge..... Hose handy, combustibles cleared from the area, firewatch afterward

gettinthere · 15-12-2010, 04:15

My coupler would not come off the shaft so I drilled a series of holes into the coupler at the key. That prevented me from drilling through to the shaft, I drilled into the key instead. I then 'connected the dots' of all the drill holes and split the coupler on the shaft.

Do not use a slide hammer to try to pull the coupler off, you can do damage to the trans.

New couplers are available from Marine Machining in Michigan. You will need to have a new coupler matched to the shaft. They never mate perfectly, the coupler is made a few thousandths too small on purpose. You'll need to have a local machine shop custom fit the coupler to your shaft.