ARB problem-RD116

Just installed a new arb in my front D44. It locks up without a problem, but it won't cleanly disengage. If you turn one hub, it feels like it's still partially engaged. It will hold, then slip. Not sure what I could have done during the install to cause this, or if it's an internal problem that came with the new locker. Could use a little help in trouble shooting this issue. Thanks.

Did you set up the ring and pinion? Do you know what you are doing with gear set-ups?

Yes, I set up the ring and pinion. I have to admit it was my first with a modern differential--I've set old Fords when I was a teenager. After numerous pinion depth/backlash shim changes, I had a professional mechanic friend of mine confirm my final setup. The pattern is good, backlash at .008, and installed with .012 additional shims for carrier pre-load. Back lash didnt change after final install. Also, no binding is evident when rotating the pinion or ring gear. I didn't try rotating an installed axle until I had installed the assembly under the Jeep. That's when I completed adding knuckles, spindles, etc.
When locked, the axles/hubs turn without binding or noise. It's when I "disengage" the locker that I get "catching" when I rotate one hub/axle or the other. By marking one hub and turning the other, I can tell the marked hub turns in the same direction as the one I'm turning--hesitantly--even though the locker is "disengaged". Any thoughts on what would cause this symptom, especially setup shortcomings, would be greatly appreciated.

OK, sounds like you checked it all out correctly.

In some situations, with a new ARB, there is a bit of heavy assembly grease caught in and around the locking mechanism, making it difficult to engage/disengage. Fill the diff with oil, run to around a bit with the hubs locked, and work the ARB. I'm betting the tight interanl tolerances are packed with grease and need to break in a bit.

Thanks for the encouraging comeback. As soon as I finish with the brakes & steering (awaiting parts), I'll do that.

Yeah, I was going to ask if the diff had fluid in it...

Yep on the fluid. Double checked to make sure it was still full after the initial fill.

I read kind through this kind of quick, but do you hear it bleed off the pressure when the valve clicks off? 4 or 5 years ago I had a couple with the port plugged in the valve.

Yea, one of the first things I did was to insure the solenoid was venting. I also removed the air line at the diff and inserted a wire into the tube to insure it wasn't clogged.
I also talked to a tech at ARBUSA, in Washington state. After describing the symptoms, his opinion was that I have a "tight" locker, and that there is probably nothing wrong. It should loosen up during initial break-in. He said there was no way the locking mechanisms could be partially locked "--it either is or it isn't". The fact that I can hold one hub from turning by hand, while the drive shaft is turning via engine power supports his opinion. We'll see. Of course, I want to believe him. I don't really want to pull the locker out, unless it's necessary.

Just a follow up on my original post. I got my steering and brakes finished yesterday, so took her out for a test run. All seems to operate correctly. No noises, etc. Locks/unlocks at will, no problems. My first experience driving with a front locker. As is always reported, Jeep wants to go straight when locked up. Feels like I've lost power steering when more or less going around easy bends in the road. I was advised not to do sharp turns until the locker has some time on it, so didn't try a "3 point" turn.