Help Diagnosing Locker Issue

[Bud125]

I was out wheeling yesterday and was going up a new to us trail and it got pretty tough so I was locked up front and rear with the stock Rubicon lockers when the rear dif light started to flash and there was a mechanical clicking noise was coming from the rear of the Jeep. The trail was still tough going so a little hard to be sure where exactly the noise was coming from. I tried unlocking both difs and after some maneuvering they unlocked. I got turned around and started heading out and needed the rear locker again so I engaged it and it went right in and made no abnormal noises. I went the rest of the day with no trouble but the noise along with the flashing locker light convinced me there was a problem so I drained the fluid today and there was no metal on the drain plug and I pulled the cover and there was nothing obvious to me. Could this be a locker pump problem? Any ideas?

 

[Jerry Bransford]

It sounds like you might have engaged that rear locker too late for it to engage in tome for the obstacle. Lockup requires a bit of differential wheel speed between the sides so the locker's tongue and groove locking parts can engage. If both sides are rotating the same it could take a long time for the locker to engage. That flashing light was indicating it wasn't locked up properly so that seems to jive with that scenario.

On such trails I engage my locker(s) well before it would be needed so it has time to lock before it's needed. On most trails I just leave them locked unless I need to make tight turns. Also make sure to never lock it while you're at speed, I engage mine while at a standstill and then drive slowly in an s-turn or two until it's locked and the flashing light goes solid.

 

[Bud125]

Thanks for the reply Jerry, the rear locker had been engaged for about 20 minuets and the front for about half that. I have read a lot about the Rubicon lockers and try and lock them sooner rather than later. I plan on moving my pumps up to the engine bay and will check all the wiring and air tubing at that time. I am glad that there is no obvious damage but it makes me wonder what went on.

 

[Jerry Bransford]

Once your pump shuts off after the locker locks, does the pump stay off? Does it ever cycle on-off-on?

 

[Bud125]

I am unsure on this, it normally locks in pretty quickly and has not given me any trouble up to this point. I did do the lockers any time mod a while back but no trouble until now.

 

[Jerry Bransford]

I am unsure on this, it normally locks in pretty quickly and has not given me any trouble up to this point. I did do the lockers any time mod a while back but no trouble until now.

I'd park the Jeep inside somewhere where it's quiet and engage the lockers with the engine off. Listen for the pump to shut off, then see how long it takes for the compressor to cycle back on indicating the pressure has dropped off.

 

[Bud125]

Good idea, I will try this. It may take me a few days as tomorrow it is back to work. Thanks!

 

[BryantJT]

My front locker was similar when I picked up my Rubicon in 2018. It would engage and then it would blink and then solid for a bit then blink some more.

Doing as suggested, I parked in the garage and had all 4 tires off the ground and engaged both lockers. They cycled and engaged, verified by spinning the tires by hand but the pump would keep cycling every few seconds. I had a pin hole in the elbow going into the front housing. I mixed up some 2 part epoxy and applied it liberally. Problem solved and holding for 2 years so far.

The oem lockers only run around 5psi if I remember right. If they were ARB or others I would have been looking at replacing the elbow due to higher pressures.

 

[HYRYSC]

I'd park the Jeep inside somewhere where it's quiet and engage the lockers with the engine off. Listen for the pump to shut off, then see how long it takes for the compressor to cycle back on indicating the pressure has dropped off.

I second this. I am a bit anal about my ARB since it is the first air locker that I have had, I do this before and after each wheeling trip. Mine has yet to cycle back on yet after about 5 minutes, but still better to be safe than sorry.

 

[Bud125]

Thanks for the replies, and yew this is the plan as soon as I can. This is the first time it has done it in the year that I have owned it. All this plumbing is old enough to be suspect.