1989 Force 125hp propeller torque

fishbait2

Cadet
Joined
Apr 18, 2008
Messages
28
I have a single exhaust gearcase with two piece driveshaft that I had installed a kit to remove the shift shaft bellows. Now I am reinstalling the gearcase and will install the propeller. But at this point I can't find the proper torque for the propeller nut. Does anyone have the answer to this question?
 

topgun3690

Ensign
Joined
May 7, 2019
Messages
987
These quotes are from the late Frank A. (RIP).....he gives a great explanation for proper prop nut torque.......

"The prop nut should be a nylock self locking nut and a little past snug should be tight enough. If the lower unit uses the Mercury style nut with tabbed locking washer, the nut should be snugged down to the next tab past snug and the locking tab bent over into the slot on the bronze hub"

"DO NOT USE AN IMPACT GUN!

The shaft splines keep the prop from rotating on the prop shaft and trying to back-off the nut.

The nut and washer simply keep the prop seated against the thrust washer behind the prop. It does not need to be "Killer" tight. If you snug the nut then give it a little extra, there is very little chance of losing the prop.

My 1988 factory manual does not give a torque value for that nut, however, I have heard values as high as 55 foot pounds given. In my opinion, this is way too much. Last time this question came up, I was so curious that I went down to the garage and checked the torque on all my engines. Average torque on prop nuts that I tightened by hand was 8 foot pounds. As stated above, being a nylock nut, it will hold itself on the threads quite nicely."
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,958
The Nyloc nut: if it comes loose too easy??? It can turn itself and fall off along with the prop and hardware.
Had one come loose, luckily it was still on the ramp and could be seen when the water calmed down.
The owner had just bought a new stainless prop. $450
 

The Force power

Commander
Joined
Feb 3, 2019
Messages
2,300
The problem with Nylon nuts;
If backed off & remounted various times, the retaining on the tread becomes less & less efficient.
In critical cases (maybe not a prop lol) they're mend to used once.
What you can do (if so desired.........) warm up the nylon & press with a flat screw driver into the preformed tread-pattern, let it cool and re-use the nut
 
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