Axle nut threads wore smooth on both sides of both new axle and hubs , nut cutting into axle spindle

Anyone seen this ? Replaced both hubs within last year , now they have wobble in wheel , took wheel off axle nut threads wore smooth and nut appears to be cutting in too axle shaft can see metal shavings ? Any help please

 

Why do the nuts look like they went thru a war?

 

It looks like an ongoing problem. Someone beat the heck out of the castle nut probably to get to some of the remaining threads on the axle. Does the castle nut have messed up threads too? If my truck had axle shafts looking like that, I'd replace them.....with a D60 axle. But new/pull your part axle shafts would be my suggestion. And if you don't want to pull them, car-parts.com (online salvage yards) is a place to start unless you want new.

 

I'm a little confused on this but a few observations:

1) on the side with the cotter key in place, there's virtually no way the threads have been actively "doing" anything because nothing could turn. What happened to the other cotter key?

2) I can't tell you why but on some stub shafts the threads were deliberately turned (ie machined away) to behind the hole for the cotter key. You don't need threads outboard of the hole, they serve zero purpose. I have chucked up axleshafts before that were damaged on the nose and turned back the threads myself for this very reason. (I found a fun way to wedge the yoke ears against my 3 jaw like a drive dog and then press it into the chuck with a live center using the center-drilled hole in the shaft).

3) are you sure the play you're now feeling is wb hubs and not ball joints? They'll present the same without a visual inspection behind the knuckle

 

Again, I've seen some OEM shafts come this way so it's not my unique idea

Also, for general knowledge: I believe it's 1-1/8 - 18, ie 1.125" - 18

 

Somebody didn't have the correct socket and used a screwdriver/chisel and hammer ....

 

This! It looks like they did the same thing putting them on(marks on the bottom part of the castle section).

 

That makes more sense of anything I could think of!

Also, has anyone ever seen these nuts self-tighten, regardless of left or right side?

I find it hard to believe they'd self-tighten and strip threads. If anything they'd want to loosen and even that would be unlikely to damage threads because the stub shaft splines hold the threads square to the shoulder of the hub.

The cotter key -- as I understand it -- is not to protect threads but to keep the nut from backing off in which case the wb hub can begin to separate under load. I guess if the nut completely fell off the shaft could float inboard and you'd be at risk of steering locking up, too.....

 

The nuts can't move. That's what the cotter key is for. Over time though, considering where they hang out.... they corrode, and the axle and nut do their level best to 'become one'..... That, and they get torqued to some truly stupid values to begin with. (north of 180 ft/lbs..... as they also hold the bearing together.) Threads get damaged when the nuts are either too loose, and the stub can bounce around in there, or, get overtorqued, and damage the threads. Putting a damaged nut on there can indeed to a real number on the threads.... same as cross-threading the nut.

Looking at the pics, I would be real tempted to replace the outer, nuts, washers, cotter keys.... just to be sure my front end stayed together. Losing an entire wheel/tire at speed is just WAY too exciting.....

 

I'd do all that but also run a re-threading die over the threads and just delete the threads outboard of the hole as shown.

OP could just yank the shafts and take them to a machine shop and say "Make threads more gooder."

The next question becomes where the play is coming from as OP reports. If both wheel bearings are new have they really both already failed?