Original lock nuts - Trivial

[71CHEVYSHORTBED402]

Took me long enough to realize there's such an animal as lock nuts on our trucks. I've seen them for other applications, but never realized what they were.

For example, the assembly manual shows lock washers for the Idler Arm Support. Both of my trucks don't have them, and use lock nuts instead. The Tie Rod clamps use them as well.

Assuming I'm on track, you can tell a lock nut by the "tapered" head, and finger tight ends where the threads meet the head.

Just wondering, what are these called other than lock nuts? Searching for nut types, they don't seem to come up. http://www.mikesenese.com/DOIT/2011/...s-and-washers/

[Keith Seymore]

At GM we call them "prevailing torque" lock nuts; I see that the McMaster Carr catalog calls them "distorted thread" locking nuts.

K

[71CHEVYSHORTBED402]

Originally Posted by Keith Seymore

At GM we call them "prevailing torque" lock nuts; I see that the McMaster Carr catalog calls them "distorted thread" locking nuts.

K

Straight from the factory and good to know, thank you. McMaster: https://www.mcmaster.com/#distorted-...-nuts/=19zj811

[Steeveedee]

For applications where high heat (such as exhaust manifolds) one can use nuts with nylon inserts. The modern replacement for that is Loc-Tite(R).

[dflarsen77]

Can you reuse lock nuts? There's a bunch that I've taken off but I thought I read it's not good to rease them.

[Steeveedee]

If they develop a good running torque, you should be able to reuse them. But if they don't fight you going down, throw 'em out and get new ones.

[71CHEVYSHORTBED402]

Originally Posted by dflarsen77

Can you reuse lock nuts? There's a bunch that I've taken off but I thought I read it's not good to rease them.

I once heard that about lock washers. I figured it might be you're just as well to replace them. I think what Steveedee makes sense.

[camtoys1]

its called a stover nut

[camtoys1]

http://products.coburnmyers.com

[Keith Seymore]

Originally Posted by 71CHEVYSHORTBED402

I once heard that about lock washers. I figured it might be you're just as well to replace them. I think what Steveedee makes sense.

"Lock washers" don't really provide any torque retention.

The "slice" is just a function of how they are made, basically in a coil which is cut once per rev (like a slinky cut into pieces).

K

[71CHEVYSHORTBED402]

Originally Posted by Keith Seymore

"Lock washers" don't really provide any torque retention.

The "slice" is just a function of how they are made, basically in a coil which is cut once per rev (like a slinky cut into pieces).

K

Ever see a split lock washer used with a "lock nut", factory? Seems the 5-16-18 bolts used along the perimeter of our steel beds may use that config. I can't confirm though. because my good bed isn't here. The other is rusted up and I busted a bolt attempting to confirm. The nut stuck right where you'd expect the torque to begin.

Interesting write-up on split lock washers, etc. I never could understand why split washers work. According to this they don't: https://engineerdog.com/2015/01/11/1...out-fasteners/

[kwmech]

I think Rockford calls them a Type C nut I guess the C is for crimp

[MJN]

We also call them 'prevailing torque' nuts here at Deere. This is a great website for about anything you need to know about locknuts.


http://locknutwhisperer.blogspot.com/

[harpo231]

google NY-LOCK

[mike16]

Originally Posted by Steeveedee

For applications where high heat (such as exhaust manifolds) one can use nuts with nylon inserts. The modern replacement for that is Loc-Tite(R).

Actually I dont think you can. There used to be three different colours representing three levels of resistance to heat. I dont know of any that resisted heat that an exhuaste manifold experiences. Not in avaiation industry anyhow. but thats a mute point because the chinese flooded the market with nuts with nylon inserts of many different colours and now you cant tell what your buying. Vendors can make all types of claims but unless they are the manufacturer, there is no telling what is what. But you can get them in a veriety of neat colours to match whats under your hood

[71CHEVYSHORTBED402]

Couple of additional spots that use lock nuts:

• Assembly manual shows a nut, washer and lock washer for steel bed to frame bolts. My 71 & 72 used a lock nut instead of the lock washer. So, washer, regular nut and a lock nut. Never could understand why it was set up that way, now I get it.
  
  
• Assembly manual shows a nut and lock washer for the bolt clamp that secures the steering column to the column cover at the firewall. Threw me a curve not having that lock washer when I pulled the column, but now I realize it must have been a lock nut.
  
  
• The front E-brake cable attaches to the equalizer using two nuts. Dollars to donut holes the rear nut locks.

Found a few more:

Push rod to brake pedal assm.

Combination prop. valve to its bracket.

Master Cyl to brake booster studs.

Brake booster studs to brake booster brackets.

Potentially the clutch fan. Mine just had regular nuts on it, which is wrong. Book calls for lock washers and nuts.


With the nylon lock nut business, from what little I've read you don't want to use those with high heat. If I remember right, the exhaust to manifold nuts are brass. They may be distorted thread.......... I only know enough to be dangerous, but I wouldn't use a nylon nut for anything outside light applications.

[Steeveedee]

Yes, the double nuts on the parking brake adjustment are for locking. Exhaust pipe to manifold nuts are steel. And no, don't use nylon locking nuts on the exhaust. The nylon just runs out when the exhaust gets hot enough.

[71CHEVYSHORTBED402]

Originally Posted by Steeveedee

Yes, the double nuts on the parking brake adjustment are for locking. Exhaust pipe to manifold nuts are steel. And no, don't use nylon locking nuts on the exhaust. The nylon just runs out when the exhaust gets hot enough.

Ah, "brass colored" steel. Probably yellow zinc.