ARB Locker Bulkhead Fitting

A previous owner installed an ARB locker in the rear diff but never hooked it up.

I know that at some point ARB changed the bulkhead fitting. Can anyone tell whether I have the new or old bulkhead fitting and if ARB 170114 and their 6mm black tubing will do what I need?

I'm a little concerned that the copper tube isn't clearly visible, but I know the locker works.

 

You might have to pull the 3rd if you can't find the copper tube inside that hole.

The bulkhead fitting locks the copper tube in place with an o-ring and pressure, and locks in the hose. Without the copper tube, you're just pumping air into the diff (and eventually out the breather).

 

Aw shoot ok.

Am I best off getting the ARB bulkhead kit, unscrewing the bulkhead body that's threaded into the third, fishing the tube out, pulling the tube through the bulkhead body, putting the o ring around it, and installing the compression fitting? Assuming I can fish the tube out?

 

That's probably what I would do (barring someone being able to positively ID which version fitting yours is... I have ARBs myself, but installed them long enough ago I don't remember what the fittings looked like)

 

I would remove the diff for peace of mind, make sure there is a locker in there, make sure the seal is there with the copper tube attached correctly.

I would also be highly suspicious that someone went through the trouble of adding a locker and not running the tube to the bulk head. You'll be getting into more work than you originally thought, but sometimes you have to start form zero to make sure shit gets done right.

Here is what the seal looks like.


On the diff -- here you can see the copper line to the bulk head route.


Full install video in case you want to watch it, I go over the fittings in the video as well.

https://youtu.be/l7761dWsBtY?si=1jgXDGXbVU2o7BbE

 

That makes sense. My thought was that the locker was installed and the copper line slipped out of the bulkhead body. I've verified that there's a locker in there, the diff only takes 2 qt of oil and when I jack up the rear axle and hook up a compressor to the fitting, the diff locks and the wheels will only turn together.

I'm going to start by pulling the bulkhead fitting and seeing what I see.

Is it possible that the copper line is attached to the bulkhead fitting in a way I can't see? Because the locker definitely works.

 

The main thru fittings look very similar. One has a deeper interior thread than the other but either way like everyone said you’ll want to take it apart. I swapped out my old fitting for the new fitting design when I was changing locker seals. I like the new design more. Allows use of a pneumatic push fitting for the new 6mm diameter air line.

The kit I bought had the airline and fittings to be able to swap on the arb compressor.

 

Sounds good, I gave summit racing more of my money so in the next week or so I'll have the 6mm tubing and new style bulkhead fitting. Once I've got parts in hand I'll start taking it apart.

 

Happy to hear it locks, then the line should be on and working. Small celebration!

Picture break down of the internal and external fittings. This is a general idea, your could be different.








Here is a link to ARBs breakdown of the fittings.

https://www.arb.com.au/assets/air-lockers/4-01.pdf

 

Thank you! This is super helpful!

Do you still think it's worth pulling the bulkhead body, or just installing the new fittings on the old body (assuming they're compatible)? I'm inclined to leave the bulkhead body in there and not mess with the copper line unless there's a compelling reason to.

 

I agree with you about leaving it.
If it's compatible I would test it first a couple times, before removing the fitting. Once or twice, wheels in the air to make sure it locked. Once that works I would test it on the ground to get some resistance in the yard, really just to make sure it's holding pressure under normal operating conditions. If that checks out, run with it. No need to remove the bulk head fitting.

 

Sounds good! Thank you!

 

I think that's the older bulkhead, but if it works it works. I'd test it with a leak down after getting it hooked up and then consider it good to go.

 

My money Is that the dude pulled the locker and installed the OEM stuff. Hopefully I’m wrong.