Shaft coupling removal

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Leeward III

Veteran Member
Joined
Jan 10, 2016
Messages
35
Location
USA
Vessel Name
LEEWARD
Vessel Make
Grand Banks 36, #806
Replacing a dripless shaft seal and I am concerned with removing the coupling from the shaft. Grand Banks with cats and MG-507 transmission. Have never attempted this with this coupling. Any info or drawings of the coupling would be a great help. Going back to the old bronze style stuffing box, tired of the leaking and spray.
 

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Generally in that type of coupling there is a pin (2nd picture) and two set screws. Drift the pin out and remove the two set screws. If the coupling is frozen on, get two longer bolts (that hold the coupling to the transmission flange), and put a ratchet socket between the shaft and the transmission flange. Then tighten the two longer opposing bolts to push the shaft out. It requires multiple repetitions stacking one additional socket each time. Lube the nuts and bolts as it will likely take a lot of tightening.

Ted
 
I'm not sure that I would be comfortable using the existing transmission flange as part of a coupler puller. If you bend the tranny flange in the process then it needs to come off to get fixed.
I would use a piece of mild steel plate instead.

Face the coupler (ideally when it's on the shaft) and align things to within 0.003" and you should be good.
 
I posted this on another thread a bit ago. This is what I made to pull the couplers off, works well.
 

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I will add this: Give yourself a time limit to trying to remove the existing flange. If you can't get it off in that timeframe, take a angle grinder and cutoff disk and cut it down where the key is. Drive a chisel down the slot and it will come right off. New ones are not expensive. The only downside is you will want to contain the cuttings since they can end up rusting and making a mess. I see people taking days fighting taking a rusted coupler off and it's just not worth it.

I hope for your sake it comes off easily.
 
A pro might not even try to slide a coupler off, he'd just hit it with the sawzall and be done with it. A 5 minute job. Even if not intending to replace the shaft, the time involved getting it apart could cost more than a new one. And then you still have an old shaft. Trying to force it off just isn't worth the time and effort. DIY is different of course, but there has to be a point where you just give up.
 
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