Fastner Question

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moparspares

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Why the slots in this nut which is original from a rear spring shackle/hanger. I assume it has something to do with gripping better to bolt and prevent unwinding but not sure.

I notice now many aftermarket spring hardware comes with nyloc nuts instead of these slotted nuts.

slotted nut.JPG
 
Its a lock nut. There are several types of lock nuts that all provide a varied degree of locking for given situations.
 
Looks like a "Castleated" nut. Designed to accept a cotter pin, like ball joints and wheel bearings.
Got the name since it looks like a Castle turret...
Screenshot_20200729-212410_Google Play Store.jpg
 
Why the slots in this nut which is original from a rear spring shackle/hanger. I assume it has something to do with gripping better to bolt and prevent unwinding but not sure.

I notice now many aftermarket spring hardware comes with nyloc nuts instead of these slotted nuts.
Yes, the Nylon locking nut is an updated version of the old lock nut.

View attachment 1715569857
Yes, the nylon lock nut is an updated version of the lock nut.
 
My vote is lock nut.

The openings look too small for a cotter pin.
 
Seems out of place on the leaf spring though, all the shackles I've encountered had crimped end nuts. Older year ?
 
Looks similar to a "flex type" locknut only with full hex.
upload_2020-7-29_20-44-1.png

Provides 6 points mechanical lock around the bolt rather than 2 or 3 flats.

NyLocs are not as reliable as a mechanical locknut.
 
Had a castleated nut loosen on a dirt bike shock. Cleaned it up and used thread locker. Came loose again. This time- tightened the nut, drilled hole through the bolt and put a cotter pin in it. Never cam loose again. Nothing more positive than a cotter pin.
 
Most lock nut are considered a 1 time use. Sometimes they ruin the bolt or stud they are threaded on.
 
I can see, I confused the Locking nut with the Castleated nut.
The Locking nut version has much tighter slices, and it cannot fit a cotter pin. Im thinking those areas flex and kep it locked.
The Castleated nut has a wider opening for the cotter pin, and dont flex. Like even the older original Mopar ball joint Castleated nut has only 3 wide gaps for the pin.
Make sense?
 
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Most lock nut are considered a 1 time use
Grade B's mechanical lock-nuts I believe are rated for 3 removals (meets a min removal torque for three installs and and removals on the same bolt). Grade C's I believe are rated for 5. Aerospace flex type are like 15 removals.
 
That is not a castle or castellated nut. Those type nuts are for cotter pins. That nut is one form of many, "mechanical lock nut."
 
Those top nuts don't run on with your fingers. The slits were cut to allow compression of that end so the ID would be a few thou smaller, creating a mechanical friction fit. They lose it after a while, didnt know 3X, thats nice to know. More common on the U-bolts were the crimped end style that had an embossed round end.
 
Grade B's mechanical lock-nuts I believe are rated for 3 removals (meets a min removal torque for three installs and and removals on the same bolt). Grade C's I believe are rated for 5. Aerospace flex type are like 15 removals.

Good rules of thumb.

What I hate is when a new component (like ball joints, tie rods, etc) that used a castle nut and cotter key is replaced with a lock nut. The factory torque spec goes out the window due to the added friction to overcome the locking feature.
 
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