I had an ARB locker installed in my 2006 Jeep Wrangler Unlimited. After the shop demo'd it numerous times, I turned the lockers off and drove home, about 40 miles. When I got home I found that the rear differential had blown all of the fluid out of the breather.

When I took it back to the shop this morning, they could not explain what happened, fill the diff and sent me on my way.

I suspect that the issue is an air leak within the differential. I think that when the compressor is turned on and the rear locker is activated, the differential is pressurized with air, which displaces the fluid, causing it to be pushed out of the vent.

Has anyone heard of or seen a similar problem?

i had a similar problem at one point. it is as you guessed. there is likely a leak in the housing {air}. either the copper line got damaged, or a seal within the locker itself.

i hope your installer stands behind it for you. be sure to monitor it.
air it up and see what is happening down there.:wave:

With the lockers on, does the compressor cylce alot? and is the oil coming out of the diff breather or the ARB solenoid exhaust port?

The oil is coming out of the diff breather. i jacked up the rear of the vehicle today, and the locker is not engaging.

sounds like a bad o-ring, most likely from an improper install.

thats a bummmer.. take it back to the installer.

Did they drill the relief valve under the carrier bearings (I think) to allow the oil to drain back out of the tube?

ARB changed the carrier in the D44s about a year ago, the install directions are different. There are quite a few posts on JU about this. The symptoms are the same as you describe, oil shooting out the breather tube.

Did they drill the relief valve under the carrier bearings (I think) to allow the oil to drain back out of the tube?

ARB changed the carrier in the D44s about a year ago, the install directions are different. There are quite a few posts on JU about this. The symptoms are the same as you describe, oil shooting out the breather tube.

I had to re-read the original post.... If the oil is being pushed out when the locker is engaged (switched on) and it's not engaging, then that's o-ring seals.

If oil is being pushed out the breather tube on the hiway (not engaged), that's an axle tube drilling issue.

I had the latter problem. My installer skipped that step and 15 miles up the hiway it was blowing oil out the breather tube. But the locker worked fine. I just had to remove the cover and drill out the axle tubes on both sides per the install manual. He bought me a couple of WARN diff guards for the hassle, so I was satisfied.

Ok, after looking at what is REALLY happening, I have learned that the problem is happening when I drive down the freeway. It is clearly an oil drainig problem. I spoke with ARB USA, and they stated that the 2005 and 2006 D44 axles lack proper drainage when the locker is intalled. The oil cannot drain down into the diff, and enters the axles tubes and is pushed out through the breather. The installer skipped that step too, as this was never a problem before.

Dropped off the Unlimited this morning to have the problem rectified. I got a custom Cat back exhaust system at cost for the trouble.