91 Mariah with a sheared prop shaft

[jasun]

My buddy has a 91 Mariah that his parents own and has been in his family since it was new. Last year on the lake something happened and they must of hit something and it sheared the prop right off.
Told him I’d give him a hand fixing it.

Plan is to remove the shaft, remove the rudder and check it, inspect the strut, replace strut bearing, repack the rudder if it is ok, replace the prop and shaft and repack the shaft.

My question is on a new prop shaft, do they fit the old coupler? I noticed on skidim it was asking for shaft length, shaft diameter, and coupler diameter. Can the new shafts can be installed from the bottom of the boat? I assume I don’t have to pull the motor to install the shaft? Any input is appreciated.


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[Sdc77]

Hey Buddy, I did mine last year. It's very straigt forward : Unscrew the coupler from the transmission, slide it and there is a big nut Inside of the coupler that retain the shaft. Unscrew, then the shaw can be pulled from the outside.
I sent it ta a shop, and the ship me back the old shaft and a new one. Didn't have to give dimension etc. they simply rebuilt it from scratch.
Don't hesitate to change also the hydrolub rings.

Good luck

[michael hunter]

Send the old shaft to General Propeller they make them and will duplicate the shaft to fit your cuppler. The shaft will go in from the bottom.

[scottschmitt]

There is this tool to pull the coupler, if you need it: https://www.skiboatpartsonline.com/i...&search=puller

Wonder if the old prop wasn't lapped properly?

[chris young]

That would be my take. The shaft broke at the key way. If you don't want a re-occurrence lap that prop. The beauty is you can lap it easily when both the shaft and the prop are out of the boat. I did mine by making a very simple adapter so I could spin the shaft in a drill and just put the prop on the floor. I doesn't take much with this method (I went too deep but it still fit ok). BTW I'm not sure which type of coupler you have, but for the keyed couplers with bolts, it is recommended that you get a new one. It should be snug enough that you have to tap it on, if you can just slide it on, you need a new coupler.

[chris young]

BTW you probably don't need a puller for the coupler, although it is a bit easier with one. As most on this forum know or have done, just find a socket that is nominally smaller than the shaft, and 4 longer bolts. Separate the coupler from the tranny, place the socket in between and install the longer bolts. Tighten the bolts evenly and you should be able to push the shaft right out.

[mike2]

If your still looking I have a shaft from a 91 miriah. The boat had right at 300hrs on it believe it or not. Owner past away and kids let the boat rot away in a field. Let me know