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Installing the Prop-Tight Propeller Locking Nut

1. Fit propeller and key stock

After the propeller and key-stock have been properly fitted on the shaft, a standard full size nut should be used first to push the propeller hub as tightly on the taper as possible.  If you have a specialized tool for installing and removing a propeller, then you can skip this step.


2. Remove full-size nut

Remove the full-size nut and replace it with the jam nut and tighten. 

3. Install Prop-Tight locking nut

Now you are ready to install the Prop-Tight locking nut. Take a pencil or a sharpie and mark on the flat of the jam nut where the cotter pin hole is located. Position the shaft so the cotter pin hole is easily seen while lining up with the slots of the locking nut.

Screw on the locking nut by hand until it makes contact with the jam nut. Since course threads tighten so quickly, you will most likely only be able to advance the nut one or two slots clockwise to line up with the cotter pin hole. 

4. Install cotter pin

The cotter pin can now be installed with the loop running fore and aft and sitting down inside the slot for a lower profile.  Bend both ends back or trim one end flush with the top of the slot and bend just one back.  Now the nuts are locked stationary in place.

Stuck between the slots?

If the cotter pin hole were to fall between two slots and you can’t tighten the locking nut anymore, mark the slot on the locking nut you were trying to line up with and then back off the locking nut to get it out of the way.

Put a reference mark on the jam nut and the hub of the propeller. Put the wrench back on the jam nut and tighten it a few degrees or the distance that the slot needed to go to line up with the cotter pin hole. Now reinstall the locking nut and tighten to the slot you had marked.

REMEMBER: you must always line up the slot with the cotter pin hole while turning the nut in a clockwise direction.  Never change direction and turn the nut back one slot to line up with the cotter pin hole.


Need help?

For additional information or questions call 410-650-2219 or send us an email here.


with the Prop-Tight Propeller Locking Nut