About 1:18 is a good sample...https://www.youtube.com/watch?v=raXy...ature=youtu.be

 

Was the entire rear axle not turning? Or, was it just the one tire on the passenger's side?

edit:
Another viewing of the vid shows only the one tire was not spinning. So, it appears to me the ratcheting is the rear locker dog clutch teeth have rounded off.
If that's what it is, you need to open the diff and look for metal in the oil before you damage the gears and bearings.

 

Wouldn't that make it happen in 2 or 4WD? It only happens in 4WD, that's why I thought it might be the chain. But I guess if it's "locked" that would indicate an issue. What's the best way to determine?

 

Have you done the locker bypass mod? If not it can't happen 2wd, since you can't lock it in 2wd.

Look at this thread, to see the dog clutch's square teeth. https://www.jk-forum.com/forums/stoc...-study-263666/

The locker can take only so much torque before the teeth give up the ghost. Once it ratchets, it becomes progressively easier to make it ratchet, until it's just a noisy open differential.

Drain the fluid before you drive it much farther, and remove the cover to inspect the oil and inside the housing for metal from the teeth. Look at the gears, too, for possible damage from any metal you may find.

 

Nope. Not done the locker mod. Interesting as I searched such. I think I can control them via my Superchips as well Nonetheless...it sounds like you're on the right track and I was wrong. Best to get it right. So, I am guessing I'd have to pull the axles to see if I messed them up as well?

 

Wouldn't hurt to look at the axles. I've seen post on here showing twisted axle shaft splines.

 

You can tell by the video that I wasn't helping matters much with such a heavy pedal. If that is indeed it, what do you think I might expect ballpark $? Guessing I might want to have a new ring and pinion put in while they're in there?

 

If it's just the locker, look for one that is broken for some other reason. There is no parts support for the locker.
A common failure is broken wires to the magnetic actuator. You'll be able to make a good one out of the two.

Did you buy the JK new on or after July 26, 2007? If so, look into the lifetime powertrain warranty.

 

Good point on the locker. Guessing it's just as easy to do new gears too, thinking metal might have got in them as well. Unfortunately, mine was one of the first to roll off the line...no "lifetime" for me! Hell, when I got mine there was only one lift and one set of bumpers being made! Thanks so much for your help, will keep you posted.