2007 Rubicon Ultd, on a Full Traction 3.5" and 35"s. 50K Miles.

Rear locker has basically never been used- engaged maybe 2-3x since bought new and then street driven the rest of the time.

Went to engage the lockers and of course- "blink blink blink". The front locks just fine. Most of the writeups I've searched have similar symptoms, but of course most of the responses have been 'take it to the dealer'.

I tested the solenoid and i can hear it clicking, so I dropped the cover and tested it again, and I can see the collar/ring moving maybe halfway- seems like the gap is 1/4" wide and the ring, with the locker 'engaged' only slides 1/8" over and sits in the middle. I get the idea that the ring should be sitting flush against the differential, and that's what locks it.

So the question is: what would cause this? Is there any further tests that I can do to verify the locker is broken/figure out if there's something I may be able to repair?

Assuming it is toast- are there any other options other then an ARB and a stock replacement?

 

I have seen a shim cure a similar problem. The shims makes the magnet push the dog clutch further into engagement.

Actuate the locker, with the cover off, and see if you can pry the locker more into engagement. If you can, a shim may be the answer, barring some other defect being the cause.

 

So, after my original post I went outside and tried to force the collar to engage, and viola- with pressure from a screwdriver and careful slow rotation of the wheel, it locked completely (and, of course, the light stopped blinking and stayed solid). Once I pulled the screwdriver out, though, the collar slid back out to the halfway mark and disengaged it. So, I would think that a shim could certainly work- but where would the shim be installed? I also wonder if all the times trying to engage it with this issue caused some wear on the dog clutch, since you can definitely hear a light grinding noise when you rotate the wheel and the collar is only half engaged.

 

If you had it half engaged, and drove the Jeep, you may have rounded off the square teeth on the dog clutch. A ratcheting sound would be evidence of that.

There was a thread by a guy who made some shims for a similar problem as you have. I believe the shims went between the plate and the coil.

 

I think that's exactly what happened. When it didn't engage and was in a position where I needed it, I had to leave it 'engaged' so the front would stay locked. You can hear light ratcheting and the fluid definitely had fine metal particles in it which would imply the square teeth were a bit worn down.

After spending the morning searching the forum for combinations of 'locker', 'shim', 'spacer', 'coil', 'plate' and 'rubicon', I've seemingly found every thread related to installing lockers (requiring shims), spacers on coils for rubicons, etc, but nothing related to what you implied above. Do you know who may have posted it, and/or if it was on this forum or another? Since the locker still works with this minor issue, I'd really rather repair mine then replace the whole unit with another locker. Is there any other way to increase the strength of the actuator/solenoid to get it to push it further over?