Axle nut "slipping" = Bad bearing?

[nougatbike]

Hi all.

 

I have a 2004 Legacy with a known-cheap-offbrand bearing in the front passenger wheel. I recently had to change a failed CV joint, and torqued the nut to spec. About a week later, I was feeling some wobble from the wheel at freeway speeds. While checking other things, I checked the torque on that nut and it took another 1/8 to 1/4 of a turn before returning to torque spec. The nut was, before turning it again, still "pinned" to the axle cut-out. Later that night on a short trip, the wheel started popping/grinding when almost home, so I parked it.

 

Today I was messing with it and put the wrench on it again to see if anything had changed with no intention of driving it further even if it did before I figured it out; it took about another 3/4s of a turn. At this point, the wheel was completely locked and will not roll with the vehicle in neutral or gear.

 

The "wheel locked and won't turn after grinding" bit sounds a lot like a fully failed bearing to me, but the "nut keeps having more room to tighten down" bit is new. Does this sound like something that can happen with a failed bearing, or is there something else I should be looking for?

[RumbleRumble]

Did you stake the axle nut into the slot on the end of the axle?

[nougatbike]

Yes, I staked it, and the stake held - there was just more "room" to tighten all of the sudden, where it had otherwise been tight before.

[Notorious]

So you’re saying the stake held but you can turn it without the stake moving? That would mean the axle itself is rotating or it may be the wrong size. Is there any play when you tug on the CV axle on the outer side?

[nougatbike]

No, I mean that I initially tightened to spec; then I staked it. Later, I unstaked it because I was getting wobble and wanted to double check, and it gave another quarter turn before reaching torque spec again, then restaked it. The bearing began to grind several miles after this. Later, in trying to diagnose, I unstaked and it turned almost an entire turn before reaching torque spec, but the wheel then locked.

[08SpecB_DE]

A burr on the threads of the shaft or the nut could make it feel like its tight when it's actually not. Is it a press in bearing or a hub assembly?

[nougatbike]

It's a press-in. It didn't have any visible burrs that I noticed, and I did check. I should probably clarify that the transition from "runs, but makes a bad bearing noise" and "is completely locked" happened while the car was parked, immediately after torquing down the nut the last time.

 

I think what I'm going to end up doing is just buying an entire knuckle/bearing/hub assembly at the junkyard and dropping it in to get me through the amount of time it will take me to get to a press and take apart the old hub/knuckle so I can inspect for damage. Assuming those are cool, I'll drop in a new bearing/seals and swap back. It's probably the best I can do for now.

[08SpecB_DE]

Sounds like the bearing. Did you remember the retainer clip before you pressed the hub back on? I've also ran into the issue of not using the correct cup for the backside while pressing the hub into the bearing and it ruined the bearing.

[GunFunZS]

Ouch. I once had a bearing seize on me while on the freeway. You are lucky it gave up the ghost while parked.

[nougatbike]

Update on this:

 

I replaced the entire knuckle/hub/bearing assembly with a junkyard part, given I didn't trust the knuckle/hub after the CV failure. I'll probably have to replace the bearing again at some point, but it fixed it for now. The old assembly could be turned by hand once the nut was off and it was out of the car, but was audibly grinding at hand-turn speeds.