ARB Locker Experts...

[Seattle206]

I've had the RD193 ARB rear locker in my 2014 SR5 since 9/2016. Installed by a highly reputable differential shop recommended by ARB tech support. Shop owner has over a decade of working with ARB lockers, differentials and gears.

9/2016-12/2017: The first year I haven't had any issues with locker. I had the mini CKSA12 compressor which held pressure and locker stays locked. Rarely did it cycle while the locker was engaged while on a trail.

12/2017-1/2018: I noticed that with the locker engaged. The compressor would cycle more than usual. This time air was coming out my rear diff. breather. The shop took apart the ARB and replaced the bonded piston seal. This fixed the issue as air was leaking from that internal seal. Shop was able to diagnose the problem on the work bench.

4/2018: Locker acts up again and compressor cycles intermittently or just continuously cycles. Air leaks out the diff. breather. Shop is perplexed and consults with ARB. I go into the shop for diagnosis. They couldn't figure why the ARB is leaking after testing the unit on the bench. ARB isn't sure either so they threw in a brand new locker. An ARB representative was present at the shop when I picked up my vehicle.

7/2018: Attended an offroad event. As soon as I start hitting the technical course the compressor would again cycling intermittently or endlessly. The spotters kept yelling "you got a leak in that ARB!". Even though the compressor keeps cycling, the locker stays engaged.

9/2018: Haven't hit any trails since 7/2018. I got a good deal on the larger CKMA12 compressor. Installed it and ran the locker. Again, intermittent or continues cycling and air leaks from the breather. Locker stays locked though.

* I did the soapy water test on the compressor and the bulkhead fitting on the 3rd member. No leaks found.

* I exercise the locker a few times a month. Whether I'm on a trail or pavement ie. straight road.

* No cuts or kinks in the blue air line leading to the differential.

* No gear oil in solenoid or in air line.

* Evident leak is inside the differential. It can only be the copper line, 2x o-rings or bonded piston seal. What else can it be? Air escapes from the breather.

The owner of the shop is always willing to help and has close ties with ARB. Before I reach out to them is there anything that should be looked out? The owner mentioned that my vehicle could be an anomaly and maybe some differential housing work needs to be done.

 

[Jetboy]

You have a leak in your ARB internal o-ring seal. If air is coming out the breather - your ARB needs a rebuild - again - or you have a leak somewhere in the copper line from the diff to the air locker.

My experience is that 1 in 10 ARBs fail on any given trail ride. I've kept track over the last few years to get more accurate data. And 10% is pretty consistently the failure rate on any given trip. Regardless of what your shop or ARB tells you, air leaks are not uncommon. OTOH I have never personally seen an ARB break, they are very strong. And I know people who've had them for 10 years or more problem free. I really wish they would redesign them with electronic actuation.

 

[Crikeymike]

There were many issues with the BPS (bonded piston seals) over the years, and the one that first replaced yours "might" have been from the same batch, even the one in the new locker they threw in. Not uncommon for those seals to fail, but it should last longer than it did.

There's also a possibility of deflection of the seal housing, depending how the copper tube is being run. I can't remember the full situation right now, but the seal housing would kind of lean under stress to one side and let air burp out between the 2 o-rings, and this was only in 3rd member diffs, like yours. Make sure the copper line has good slack in it, and that it's not trying to push or pull the seal housing one way or another. My Suzuki lockers used to do that. I just turned up the stereo more in between diff services, and they never failed to work, just leaked air.

You're in Seattle, so you're probably already in talks with the guys over at Mule, many of whom have worked with ARB before.

 

[atchcraft]

Mine started doing the same thing last weekend on a hunting trip. I installed the 3rd member, July 2018. I just got off the phone with ECGS, who told me that it’s most likely a defective bonded seal issue and that ARB has sent out new seals and covering everything. I’m not excited about sending my 3rd off, but it’s nice to know that ECGS and ARB are standing behind it.

 

[cutty01]

I've been thinking about getting a rear ARB locker and this is first time I hear about leaking issues. 10%, geez! I am however enthused to see that ARB and their installation partners are trying to do the right thing to address your issues!

 

[Seattle206]

Yeah, my air locker woes continue. I'm having Mule take a look in December. At this point I might throw in a Harrop E-locker.

 

[cutty01]

Does the Harrop E-locker still disengage for a 1/4 to 1/2 wheel turn after it transitions between forward and reverse momentum? That is, if you're rock crawling and you roll back to get a better line, you temporarily lose positive wheel lock for a bit before it reengages in the direction you're traveling?

I'd prefer the simplicity of an e-locker but not at the sacrifice of "always-on" locking.

 

[atchcraft]

Yeah, my air locker woes continue. I'm having Mule take a look in December. At this point I might throw in a Harrop E-locker.

Did you ever get a resolution on this? I’m still waiting for a fix on mine. I’m apparently going to get a new 3rd member next week, after ARB’s new and re-improved, we swear it going to work this time, parts come in. It’s getting old and now I’m hearing that the fronts are sketchy as well...

 

[Seattle206]

Did you ever get a resolution on this? I’m still waiting for a fix on mine. I’m apparently going to get a new 3rd member next week, after ARB’s new and re-improved, we swear it going to work this time, parts come in. It’s getting old and now I’m hearing that the fronts are sketchy as well...

I replaced the bonded piston seal in 12/2018 with ARB's most current design. So far, not a single leak yet as of 5/3/2019.

 

[mteolus]

I haven't got front lockers yet, but when I do I will get the Eaton's.

Here is a good explanation of different types of lockers. Eaton is at 14:20. Main disadvantage is that your wheel has to turn 180 degrees to get them to engage. Air locker is immediate.

 

[Inv4drZm]

It might be worthwhile to try running the ARBs at 50-60 psi instead of the full 150 or so.

It seems to actuate just fine and the seals might last longer according to the few I've heard that do this.

 

[atchcraft]

I replaced the bonded piston seal in 12/2018 with ARB's most current design. So far, not a single leak yet as of 5/3/2019.

Good to hear. ECGS is sending me out a new front and rear, 3rd/clam shell, and they're even going to foot the bill for the remove and replace. I'm hoping that it puts this issue to rest, I'm over it.