I need my control arms to go about another 1/8 shorter to get the pinion angle right. Problem is they are as short as possible right now. Is it safe to lathe off 1/8 inch from the jam nut to give me more room? It's a 1-1/4" rod end and the jam nut is roughly 5/8" to 3/4" thick.

Thanks

Jam nuts serve a very specific purpose and are almost always narrower than other types of fasteners.

I would have no problem facing a jam nut down as long as I still had a coupla threads engaged. I wouldn't start to worry until the thickness of the jam nut got below 1/2 the diameter. For fasteners, I like to have engagement of 1X diameter for most sizes. Obviously, if you go real big or real small, this doesn't always apply.

Turn away!

PT

ps-I reread your post. I wouldnn't go less thna 1/2" for the jam nut. Hope that's enough :flipoff2:

One of the "Real" engineers will no doubt chime in with a formula (I'm off to find my copy of Marks')

You can buy thin or thick jam nuts in most sizes. The jam nut only keeps the thread from turning,so 3-4 threads should work. We have turned many jam nuts down but we drill them for safety wire as well as the corner of the link end and wire tight as a backup. Good luck:smokin:

I got out the ol' Marks'. Wouldn't you know, nothing about thickness of nuts in the whole damned handbook.

I too am a fan of safety wire. Works well and gives an immediate visual indication of failure.

PT

I got out the ol' Marks'. Wouldn't you know, nothing about thickness of nuts in the whole damned handbook.

I too am a fan of safety wire. Works well and gives an immediate visual indication of failure.

PT

PT,

Jam nut is just to take up the slack. Typically 1/2 thickness of standard nuts.

If a tie rod can move back and forth in the tie rod end, it acts like a slide hammer. Just keeps pounding away at the threads due to clearance between the two. Jam nuts is to hold the thread in the tie rod end, preventing the slide hammer effect.

If you know the size you need, should be simple to order a AN316 jam nut from an aircraft hardware store.

Tom

Thanks guys. I think I've come up with an easier solution. I'm not a machinist, so rather than cut the jam nut, I'm going to cut a 1/4 inch off the control arm with a chop saw. The chop saw should give me a good perpendicular cut. I wasn't going that route at first because I was thinking of hacksaws and sawsalls. I'd never get a good straight cut with those. I should still have plenty of thread in the arm after the cut and just use the nut I have.

Am I overlooking something obvious or does that sound reasonable?

that was going to be my suggestion. jamb nuts are thin enough.

PT,

Jam nut is just to take up the slack. Typically 1/2 thickness of standard nuts.

If a tie rod can move back and forth in the tie rod end, it acts like a slide hammer. Just keeps pounding away at the threads due to clearance between the two. Jam nuts is to hold the thread in the tie rod end, preventing the slide hammer effect.

If you know the size you need, should be simple to order a AN316 jam nut from an aircraft hardware store.

Tom

Actually, the dynamic nature of tie rods and suspension links is quite a bit more complicated than that. It isn't so much the slide hammer effect as it is an elasticity issue of the tie rod end, suspension link end being under compression and then extension. These forces can act to loosen the tie rod end. The function of the jam nut is to apply a consistent force to the device being locked.

At least that's what my buddy the PE told me, and also why he tells me that slit tie rods and clamps are a better means of locking things like tie rod ends- he's also an A&P (I apprenticed with him in the early 80s).

PT