Prop-nut Question

[Latitude9.5]

OK so here's the deal, we put the new prop on today, after the prop is a spacer (this is due to extra shaft length for the old feathering prop) anyhow, the hub is a little bigger so I either need to have the spacer shortened OR there are two nuts on the prop the large nut and the jam nut, would there be any issue using two smaller nuts instead of one large one small? Of course cotter pin goes on after that.

At least you didn't ask which nut goes on first the big one or the little one. That ALWAYS starts a fight.

Two thin jam nuts are certainly not standard practice. Maybe someone can do detailed thread loading calculations to tell you you would be ok with it, but why take the chance?

Boat design is a history of tweaking things until they break, then backing off. You really don't want to voluteer to be the guniea pig here do you?

[Latitude9.5]

Yea well the issue is this, to use the spare prop, I need the current spacer, which is a stainless spacer, if I shorten the spacer, it will only work on one prop, basically I need to get a new spacer. However, if it's a risk obviously I don't want to do it, I'll just have to have a shorter spacer made. we can actually see the cotter key hole just peaking out, so it's maybe a 1/16th of an inch that I need to get the cotter key in.

[Latitude9.5]

Of course i could just go with a slotted nut that the cotter key would go through.

[fstbttms]

Originally Posted by GreatKetch

Two thin jam nuts are certainly not standard practice. Maybe someone can do detailed thread loading calculations to tell you you would be ok with it, but why take the chance?

I would be very, VERY surprised if using two thin nuts ever presented any kind of problem. Seriously, what could happen?

[Latitude9.5]

I called the prop shop asked them about running a castle nut or a second thinner nut, they didn't think it would be an issue, so i dunno, I think the castle nut will easily fit and not give up any strength.

[Latitude9.5]

ok i ended up with a jam nut that has about 25% more sidewall too it (it's beafier) stainless steal and a castle nut, again bigger nut (outer diameter, not inner) then the original nuts....... i think i'll be ok LOL