Prop Nut wants to back off

[sacalait59]

My 78 20hp Mercury prop nut wants to back off. It is a new nut, I allready lost
a prop due to nut backing off. I tighten it down and backs off. Any suggestions?

 

[Chris1956]

Re: Prop Nut wants to back off

The larger Merc Prop nuts are usually nylon lock nuts, with spider washers under them. if you bend down the spiders arms, it slocks the nut to the props. Are you supposed to have this kind?

 

[sacalait59]

Re: Prop Nut wants to back off

No I have a lock nut and a with a washer. I think the prop goes first then the washer then the lock nut, right?

 

[Chris1956]

Re: Prop Nut wants to back off

The parts list shows just a spacer and prop nut behind the prop. it would seem that either your prop nut is the wrong one, defective or maybe you are not tightening it enough. Why not try some thread locker on the propshaft. make sure the threads are grease free.

 

[lckstckn2smknbrls]

Re: Prop Nut wants to back off

Do you need a cotter pin?

 

[sacalait59]

Re: Prop Nut wants to back off

I don't think there is a hole for a cotterpin but will check what should the torque be on the nut? Thanks