View Full Version : Propeller Shaft Coupler Problems.. Help!!

05-17-2005, 07:42 PM
Ok, so were on the lake last Sunday and everything is fine. All of the sudden when we are pulling a skier up the boat is vibrating like crazy. So we stop, limp home and hope for the best. After inspecting the prop we know itís not that, so I pull the engine cover and rear cover off and have a look at the shaft, and I see that the key in the shaft has stripped the coupler where they meet, it got looser and looser and the shaft was wobbling around in the hole that was bigger now. Here are a few pictures.

close up of the slot for the key

here is a inside shot of the coupler, see the threads worn away.

The nut that holds the shaft into the coupler came loose because the screw that holds the nut in place was not tightened. The shaft is not damaged. we had it checked out.

Ok, so now I need a new coupler that matched the shaft, no biggie right? Wrong. I have no idea who made this combo since it was replaced 5 years ago by the previous owner.

I called Richard from www.skidim.com and all they sold was ARE. They didnít have one that matched the description of the one I have. He sent me to Rambo Marine who sells replacement mastercraft parts. Everything seemed fine there except the mastercraft coupler didnít have a set screw to hold the nut in place. He sent me to Marine Associates, same thing, who sent me to Marine Hardware who only sells bronze couplers.

I called the previous owner who gave me the number to the shop who replaced the shaft. They found the invoice for him but only had labor and a description of the type of service, in this case replacing the shaft/ coupler.

Any one got any ideas about who would have made this coupler/shaft.

Iím thinking of going to a local machine shop and making a replacement of this exact unit. Or should I drop 400 and get a new shaft/ coupler?

Here are some more shots to see if you have any idea on who makes this one.

1981 Mastercraft S&S Powerslot

05-18-2005, 07:02 AM
Well - you're going to drop at least $300 on a machine shop. So - if it were me, I'd go ahead & get something over the counter.

just my :twocents:

05-18-2005, 08:54 AM
I'm sure you've already thought of this...get the one from Rambo and drill and tap yourself a set screw hole (have it priced by a local shop if you don't wanna DIY)

I think I'd get something off the shelf in the end....


05-18-2005, 10:04 AM
I was going to do that, but the guy from rambo said that the taper of the driveshaft might be different on the shaft vs. their coupler. The machine shop here was going to charge me $180.

But Ill prob just go with a mastercraft part for $60 + shipping and take my chances, and this winter fix it right with a new set.