On Friday, feeling great about my front end bushings replacement / 2/5" lift (death wobble - resolved) and new rear end bearing replacement (grinding sound - gone), I decided to take to the local mud hill and see how things are off-road.

It was a rough ascent in some deep ruts. I couldn't turn out of them. So I leaned out and realized that the frront wheels were not engaged (not spinning).

I went to the locking hubs and went back to free and then to lock again.

What I noticed was that they "snap" into the free position, but not the "lock" position. I'd think that it would snap into both position.

So I took apart both hubs and looked at the parts side by side, stacked and individually. They look identical. So there's no visible damage to either. But then again, neither of them "snap" into lock. Just free.

I guess my question is: how do I know it's bad hubs? Could it be something else?

When is the last time the hubs and bearings were taken apart, cleaned, and regreased ?

Sometimes people pack too much grease in the locking hub area hoping to keep water out.

Over extended period of time the grease can get hard making it hard for the inner hub to slide in and engage.

You can always jack the front diff up and lock the hubs (t case in 2wd or neutral) and see if they turn the inner axles. If they do then it's something else. If they don't it's the hubs. My tcase bushings were worn out so bad that even though it looked like it was in 4wd the rods were hitting the cross member and not fully engaging the tcase.