Brake Rod Jam nuts

[DaWizard]

Something has troubled me since I rebuilt my brakes.

Why are there Jam Nuts on the brake rods when both ends of the rods are captured by a clevis pin and cotter pin?

With Henry being so frugal, one would think he wouldn't need the expense of this nut. What am I missing?

[Mitch]

Because it prevents the threads from pulling out of the clevis. The jam nut locks it in to prevent that from happening. It's a safety feature

[George Miller]

Mitch
Has got it. The threads would get worn over a period of time. They would get real loose then strip. There is a lot of force on those rods.

[DaWizard]

Hmmm, ya know, as simple as that seems. it does make sense. Thinking about it, if the threads get a bit worn, they would shift in the clevis and loosen up and eventually strip themselves out.

Damn clever.

[Paul K.]

On worn pins and clevises you can slightly "cock" the clevis, tighten the nut . Reduces rattle some.