Replaced prop shaft coupler in the water with split unit

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sdowney717

Guru
Joined
Jan 26, 2016
Messages
2,264
Location
United States
Vessel Name
Old Glory
Vessel Make
1970 Egg Harbor 37 extended salon model
I wanted to do this for a while since I have a vibration and the coupler was rusted and originally a used freebie. I ran it in the slip up to 1500 rpm and did not see it jumping around like before, but not tested it yet.

Used a #50500A1375 Split Buck Algonquin Marine Motor Coupling bought from Go2Marine which had the best price.

First install day was a failure, so went home to think how I was going to get this on.

The coupler is coated with some kind of rough zinc and it made it too tight of a fit to the hub on velvet drive. Ended up filing that coating off the male end so it actually slipped into the transmission hub. And had to smooth the inside of the coupler to fit the shaft.
My old SS shaft also had to file smooth where the securing set screw bolts pressed into the SS which raises a bump in the shaft.

My key is also SS and had to file smooth the key and smooth over end of the shaft keyway as it was so sharp it dug into the key and jammed when I was sliding on the coupler.

Twice I got it slid into position with key sticking halfway in, key was stuck as it raised a burr on the key
I drilled the shaft dimple for the set screw bolt, then it completely hung on the shaft and was very hard to draw off using bolts and sockets. Due I think to some metal bits from the drill jammed the coupler on the shaft.
So I left that day as a failure.

Next day, after making certain the key fit smoothly, used a big crowbar and levered it onto the shaft.
I could never have slid this on without first spreading the split end open. And using an exhaust pipe clamp to lock the shaft down.
I used 16 penny nails cut off and hammered in the end as wedges.

This new coupler is very big and long and it did just fit. I have enough room to replace the packing, and might be able to cut back the rubber hose for more room. I could have even taken off the stuffing bx in the water and plugged the flow with a rag.

I measured the face clearance at ZERO 3/4 of the way around and .002 in just one small area. Amazingly flat tight fit which shocked me. I could not fit a .001 feeler gauge in between trans hub and coupler. In one spot fit a .002, but could not fit a .0025.
Way better than the old coupler. Spinning the shaft and remeasured was all the same.

If this does not fix the vibration, then next haul will pull shaft and have prop and shaft looked at.
https://photos.google.com/share/AF1...?key=Z3FqQUhJWFZrTUVOUWVaUENfV1pPREc4TWw5djVn
 

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