Prop Nut

[lncoop]

I replaced the prop on my 2002 90 horse Merc the other day. I put the new one on just like the old one, prop, tab washer (bent three tabs), snugged down prop nut. To my knowledge that's correct. I'm just wondering what prevents the prop nut from falling off if it manages to vibrate loose somehow. I know some of the configurations employ a castle nut and cotter pin, but mine doesn't. Just curious. Enlighten me please.

 

[usskydvr]

Re: Prop Nut

The three tabs should be bent so they fit into corresponding slots on the thrust washer (or in the case of older props the slot was built into the hub).
The thrust washer is splined to match the prop shaft so it can't rotate. And since the tabbed washer is now bent into the thrust washer it can't turn either and since it can't turn, neither can the prop nut which is nestled in the tabbed washer.

 

[oldjeep]

Re: Prop Nut

tab washer (bent three tabs), snugged down prop nut.

How did you manage to do it in that order? You are supposed to torque the nut first - since the tabbed washer captures the nut and spins with it. Then you bend the tabs down. Chances are good that if you did it in reverse that you rounded out the inside of the tabbed washer and it is not doing its job now.

 

[lncoop]

Re: Prop Nut

Okay, I see what you're saying. I'll check it out and get a new tab washer if necessary. If you torgue the nut down first, how can you be sure you'll have three tabs lined up with the slots when you're done? Just know you will?

 

[oldjeep]

Re: Prop Nut

Okay, I see what you're saying. I'll check it out and get a new tab washer if necessary. If you torgue the nut down first, how can you be sure you'll have three tabs lined up with the slots when you're done? Just know you will?

There will always be 3 that are close, just turn the nut enough more to line it up.

 

[lncoop]

Re: Prop Nut

Went ahead and picked up a prop nut kit this afternoon and will be replacing that tab washer shortly. Thanks for catching that, oldjeep. You may have saved me from testing the buoyancy of a brand new prop!

 

[oldjeep]

Re: Prop Nut

Went ahead and picked up a prop nut kit this afternoon and will be replacing that tab washer shortly. Thanks for catching that, oldjeep. You may have saved me from testing the buoyancy of a brand new prop!

Chances of that nut actually backing off are pretty slim as long as it is a nylock. The washer is just one more failsafe, but good to have.

 

[lncoop]

Re: Prop Nut

Prop is on nice and snug. It will receive a weekend long baptism. Thanks guys.