Warning..please read

[Lance B. Johnson]

next you are going to tell us the key to a healthy shaft is to have a female mechanic inspect your nuts?

[MLA]

I tightened it up as well as I could but didn't have a 2x4 chunk handy so I need to try again later. Prop didn't seem to move at all. The nut spun pretty easy - one of the reasons I hate nylocks.

That prop has about 75 hours on it since installed.

You need a new nut in that case.

[oldjeep]

You need a new nut in that case.

I've got a spare, but even new they don't take much to spin.

[malibucat]

Prop appearently was not lapped to the shaft to get the prop fit. Google "Proper prop installation"......on the second page you will see a link to the Nautiquefan web site.

[oldjeep]

Prop appearently was not lapped to the shaft to get the prop fit. Google "Proper prop installation"......on the second page you will see a link to the Nautiquefan web site.

More likely the key just jammed up keeping the prop from seating that last 16th.

[formulaben]

Prop appearently was not lapped to the shaft to get the prop fit. Google "Proper prop installation"......on the second page you will see a link to the Nautiquefan web site.

More likely the key just jammed up keeping the prop from seating that last 16th.

Whether you choose to lap fit or not, the one tip I really like on this page is where you "dry fit" without the key and use a fine-tipped Sharpie to mark the fully seated prop. Then when you tighten it should make that mark disappear, so you know it is fully seated and not jammed on the key.

http://www.pbase.com/mainecruising/fitting_a_prop

[Baddog]

Talking about the air between the nut and the prop - the one that you could just about stick a dime in.

WP_20150930_002.jpg

Oh. Never mind then, old eyes, but an Old Jeep would understand that.

[Baddog]

One other important point: I never lube my shaft before covering it with a prop. A good tight fit DOES matter. And yes, size factors in. Tolerance should also be considered at all times.

[Michigan boarder]

The key can also be a cause for the prop not to mate to the taper on the shaft. The key can ride up in the slot thus keeping the prop from a proper seating, always check for that possibility.

Nut, slot, shaft, and mate all in the same post.

.....must.....refrain........from typing...........inappropriate...............reply.......................

[oldjeep]

One other important point: I never lube my shaft before covering it with a prop. A good tight fit DOES matter. And yes, size factors in. Tolerance should also be considered at all times.

Lubing a taper is always a no-no. The taper is supposed to be providing most of the holding force, not the key.

[Malibuzer]

One other important point: I never lube my shaft before covering it with a prop. A good tight fit DOES matter. And yes, size factors in. Tolerance should also be considered at all times.

BAD DOG!!!!!

[TallRedRider]

One other important point: I never lube my shaft before covering it with a prop. A good tight fit DOES matter. And yes, size factors in. Tolerance should also be considered at all times.

Lubing a taper is always a no-no. The taper is supposed to be providing most of the holding force, not the key.

Acme begs to differ. I would think they would know. Because of this, I have put a light film of grease on and found that although it still takes some beating to get the prop off, it does not get stuck on like it will otherwise. And they state the proper torque is 35 pounds.

Read step 5.

[JB-FOOT]

Not uncommon to have the newly installed prop not full seat on the tapered shaft. The worst ive seen from this is a buggered key.

or the Key not being in the slot properly, which in turn makes it nearly impossible to seat the prop properly to the shaft.

Edited October 1, 2015 by JB-FOOT

[John I.]

Acme begs to differ. I would think they would know. Because of this, I have put a light film of grease on and found that although it still takes some beating to get the prop off, it does not get stuck on like it will otherwise. And they state the proper torque is 35 pounds.

Read step 5.

Fairly certain I muscled mine way past 35 ft/lbs.

[williemon]

I thought about posting last night but I'm sure my post would have taken an off turn. I have read about using a laping compound to true the tapers to each other, then cleaning well and reinstalling. I too wondered about using a light film grease but was thinking that was a no way sort of thing. Now I think I had read about not using grease on the coupling tapers while the prop tapers may be ok. I do need to check mine for sure.

[formulaben]

Lubing a taper is always a no-no. The taper is supposed to be providing most of the holding force, not the key.

Acme begs to differ. I would think they would know. Because of this, I have put a light film of grease on and found that although it still takes some beating to get the prop off, it does not get stuck on like it will otherwise. And they state the proper torque is 35 pounds.

Read step 5.

There was a bit of an argument over this, of which I was a part...I'll stay out of it other than to say that:

1) indeed a taper does provide a LOT of friction if that is the intended purpose, and

2) the key take a LOT of torque to shear.

Have it your way.

[jtryon]

I thought about posting last night but I'm sure my post would have taken an off turn. I have read about using a laping compound to true the tapers to each other, then cleaning well and reinstalling. I too wondered about using a light film grease but was thinking that was a no way sort of thing. Now I think I had read about not using grease on the coupling tapers while the prop tapers may be ok. I do need to check mine for sure.

this is the best thread i've seen on the subject and i have followed it for all my prop installs without any issues: http://www.correctcraftfan.com/forum/forum_posts.asp?TID=12866&KW=lapping&title=proper-prop-installation

[Baddog]

For now I am leaving my taper clean. I like a clean taper and so does my wife.

[TallRedRider]

I would be willing to bet what would happen if you depended on the shaft friction to hold your prop and did not even install the key.

[justgary]

I use anti seize on my prop shaft.

I also inspect my prop and nut before every launch. No excuses for loose nuts. It's too easy to check at the ramp.

I was helping a friend launch his boat last year, so I naturally looked at his prop. He was surprised when I told him that his cotter pin was worn through and barely hanging in the hole. He was more surprised that I had a spare in my truck.