# Prop torque



## Aquahollic (Sep 24, 2009)

OK, so the manual says to torque my prop down to 40 ft lbs. When I do that the castle nut doesn't line up with the holes for the cotter pin. Do I torque it down tighter so that they line up or looser so they line up? I went looser but I was just wondering.


John


----------



## Starlifter (Feb 24, 2011)

Don't go looser; and it doesn't hurt to turn it a tad bit more to line up the castle nut. Our Yamaha F150 when torqued was the same way, so I just needed to turn the castle nut just enough to line up cotter pin. Also, make sure your using a stainless steel cotter pin.


----------



## Sequoiha (Sep 28, 2007)

Starlifter said:


> Don't go looser; and it doesn't hurt to turn it a tad bit more to line up the castle nut. Our Yamaha F150 when torqued was the same way, so I just needed to turn the castle nut just enough to line up cotter pin. Also, make sure your using a stainless steel cotter pin.


 This is correct, do not go looser, and like he said make sure you use a stainless cotter pin.


----------



## X-Shark (Oct 3, 2007)

Here is what I have found using a ratchet torque wrench set at 38ftlbs.

When it clicks at 38ft lbs...a slight more tweak tighter and the holes line up. 

It was something a learned by experimenting one day.


----------



## Starlifter (Feb 24, 2011)

X-Shark, 

This is not meant to shoot down your technique; but just as a FYI kinda thing along the lines of the original thread. The propeller shafts on outboards should easily accept at the least by the propeller shafts diameter and material makeup 100ft. lbs. of torque if not more if you were to take it that far as an extreme example though you obviously shouldn't.

I'm an auto tech by trade, and not a marine tech, but figuring by the torque and how the propeller's hub is pressed in it is probably torqued around 40ft. lbs., so that if the prop collided with something in the water the hub can break free; as well as, the nut doesn't pull on the propeller shaft, wearing out the splines, where the crankshaft meshes with the propeller shaft, when way over torqued.


----------



## X-Shark (Oct 3, 2007)

I don't understand your point?

Obviously greasing the splines once a year is part of maintenance.
As well as removing the prop for inspection anytime someone has wrapped line around the prop.

Checking several different Factory manuals...The torque is 40ftlbs.

My method is to not over torque and to line up the slot.

Have you ever had a prop that was a Bitch to get off? It's a Bitch and turns a simple job into a PITA.

And yes I do use the torque wrench on it each time.


----------



## Starlifter (Feb 24, 2011)

X-Shark,

I'm just going by my Yamaha Factory Service Manual for a F150 for my information when dealing with the issue of just torquing the castle nut. It just lists to set torque wrench to 40ft. lbs. and if the castle isn't lining up after hitting 40ft. lbs. to just turn it until it does. 

[_*another side note: keep in mind the further the torque wrench gets from the castle nut will throw the torque setting off anyways due to metal twist occurring in the extension._]

So, back to what I was originally saying in this post, this is why I said the prop shaft should easily accept well over 100ft. lbs. of torque, meaning a few pounds ,which is 5-10ft. lbs. over is nothing when going past 40ft. lbs. of torque, and that it isn't going to hurt anything.

Then I just added as a side note, I figure some of the reasons why they must set the torque at 40ft. lbs. must be for the reasons I pointed out; meaning I was making an assumption and not pointing at a mere fact here.

Lastly, if your routine maintenance is followed yearly like you listed; adding grease to prop shaft, etc.. Then, you should not have a prop freeze up on the prop shaft. Unless, it's once in a blue moon the prop shaft is inspected, and then I can see it being a pain in the ass. I don't see the torque causing it to seize. I see either corrosion or the splines fusing; freezing up a prop.

My point in a nutshell is you don't have to be that anal about setting the torque wrench to 38ft. lbs., and then turning it to align the castle. _"This is why I said I'm not shooting down your technique." _ So, you don't have to get all huffy-puffy and bow all up.


----------

