Rear diff and arb locker issue (1 Viewer)

[Indestructible 47]

First off I'll say that I'd like to think that I have a reasonable understanding of mechanical workings but I think I am more in need of experience this time.

Vehicle is a DD. 150k original miles. Factory locked, but has an ARB air locker in the rear. Not sure why, the elocker was taken out prior to my ownership. Everything was fine for a good while, before some symptoms started occurring, which I will list in order.

1. Air locker would not engage. Compressor would continually run and a strong diff oil sent became present around the vehicle. After a few times trying the locker engaged as normal. Progressively became harder to engage.

2. Steep as heck track. Serious angles, no winch point. Rear locker would not engage. A lot of right foot and the front locker engaged with the compressor trying to engage the rear we were able to get ourselves out. Locker still won't go in.

3. Dropped the diff oil. Huge amounts of metal in the rear diff. No chunks however. Refilled the diff with oil. Tested the locker, worked perfectly.

4. 5000 miles later and I need the locker. Fails me again. Just will not engage. Same as before, compressor runs continually and strong diff oil smell.

5. 1000 miles after that and today, I have diff oil everywhere. Huge amounts, like caliper to caliper spray happening. Looks to be coming from the diff breather. Is not the pinion seal, that is about the only dry spot on the entire axle.


So that brings me here. It's my DD, I'm short on spare cash but can't run around spraying oil everywhere. Gunna drop the oil in the diff, and see but I'm struggling to understand what is causing the oil to suddenly gush from the breather. The diff is not over full. Only other way out of the breather is by pressure. Water in the diff causing steam? Air locker compressor stays off when not using the locker. On the air locker, what about it? I'm certain it is responsible for the metal in the diff, where will the metal be coming from if it is the locker?

I guess I'm just looking for any help and guidance that's going to save me the most coin. Yes I can go back to the factory e locker but that's a $$$$ option right now. I know I need to pull the diff down and take the 3rd member out but I really really don't want to have to go back in there.


Any ideas and opinions are welcome, I'll be a happy man if someone calls me a idiot and points to something super simple.

 

[jonheld]

This sounds like an air leak in the internals of the locker itself.
It should be fairly easy to identify just by listening to the sound of rushing air.
You're blowing out gear oil because you're pressurizing the axle housing.

Also, the factory electric locker axle housing would need to be modified to cover up the hole left by the OEM locker mechanism.

 

[John McVicker]

Sorry, for some reason I could not copy just the link….but check this post out.

ARB Air Locker - Air Line Clearing - 80 Series​

Author: Thomas Wong (LongDuck) May 28, 2015
Finally got around to clearing out the air lines on the ARB Air Lockers, front and rear. As many may know this uses an onboard ARB compressor to provide somewhere around 100psi to the actuators inside the axle, locking rear or rear+front via dash switching. Several runs back (Mt Ord) we noticed that my lockers weren't engaging on an uneven obstacle which indicated some maintenance was needed.

Taking LCPhil's advice (given several times, and thanks!), I got the creeper under the LC and loosened the brass fitting holding the blue air line using a 12mm box-end. Note that there is a 12mm air line crimp fitting which threads into a 14mm brass mount on the axle housing. Inside of both fittings when tight is a metal air line which carries the air pressure down somewhere inside where the magic happens.

Here's the front line removed, with an old sock held over the line by twisting the metal spring through it to hold it in place - it jumps around a lot while the air line is being purged and shoots out grimy old gear oil.




And here's what comes out of it (*astute observers can see the new step endcap installed here and on the other side - which were torn off the mud some time ago).



After the line was clear of the axle housing, I turned on the ARB compressor main switch and got a quick pulse ("BRRRRR"), and then nothing for a few moments, followed by "BRRR...BRRR... BRRR... BRRRRRRR" as the compressor ran longer and longer under the demand switch to push more grease and gear oil out of the line. About 5 minutes later, the compressor was running non-stop and the goop seemed to stop coming out of the air line - telling me it was completely clear. Repeated the procedure on the back air line with the same result.

I attribute this to not activating the Fr & Rr lockers as regularly as I should since the gear oil manages to get pushed up the air line from disuse. I plan to try and make an opportunity to lock them up at least once a month to be sure the air lines stay clear from now on. Installation of petcock valves to prevent oil/grease migration up the lines seems like a hassle in the long run, but we'll see how it goes.



https://www.weebly.com/signup?utm_source=internal&utm_medium=footer

 

[mudgudgeon]

Pull the axles out,
Pull rear drive shaft,
pull the third member out,
Tape up hubs to keep dirt out,
Wrap diff centre section tightly with glad wrap and some duct tape to keep crud out of the housing,
Lock CDL,
Drive your new front wheel drive only cruiser for a while,
Diagnose and repair air locker issue at your leisure.


Idiot!


Air leak within the pumpkin sounds like the obvious cause of oil spewing out, but doesn't explain the metal in the oil.

The copper tube in the third can get contacted by the ring gear and have a hole rubbed in it. Which causes an air leak in the housing.
Maybe it got caught enough to get chewed up and spat out?

Another common issue with ARBs is the solenoids get contaminated by oil feeding back through the airline. One fix for this is to reduce the line pressure from the compressor to the lockers. A gunked up solenoid explains the lack of function, but not the metal in the oil. And doesn't obviously explain the oil spraying out.

 

[John McVicker]

This guy puts out good information too.

 

[mudgudgeon]

Also, the factory electric locker axle housing would need to be modified to cover up the hole left by the OEM locker mechanism.

Are you referring to the clearance notch?
The standard gasket and housing should still cover and seal.
The outer ring of the third member mating surface is continuous.

I've removed a locked rear third and reinstalled a standard third without any leaks in my old 105 series cruiser.

 

[John McVicker]

And one more…from @cruiseroutfit

Cruiser Outfitters - http://www.cruiseroutfitters.com/tech_ARB_troubleshoot.html

 

[cruiseroutfit]

And one more…from @cruiseroutfit

Cruiser Outfitters - http://www.cruiseroutfitters.com/tech_ARB_troubleshoot.html

I wrote that 15+ years ago.

We still love Air Lockers, a set going into an build in the shop today! You can catch a corner of it here

 

[Indestructible 47]

Wow thanks all knew I'd be able to rely on the 80 series folks. I cannot hear any air leaks in the axle with the compressor engaged and engine not running so whilst the locker isn't working as it should it's not likely to be causing the oil spray when you consider the fact that the oil spray is occurring when there is no pressure to the locker.

I'll drop the oil today and see what's up, thoroughly clean all the lines out and see what that gives me. The rear axle did see some water crossings last weekend so their might be water in the oil, causing steam to force the oil out of the breather. I'll report back later.

 

[Indestructible 47]

Ok so the investigation continues. Less metal this time opposed to the last oil change.

 

[Indestructible 47]

Ok so upon closer inspection I quickly determined that the oil leak was in fact the pinion seal. So I got to and pulled the driveshaft, and noticed that the splided flange was a little bit loose. Anyway, pulled the flange and saw a good amount of sand in the seal. The sand had not made it past the seal however.

So I yanked the seal and pulled the washer and bearing out hoping to find a solid spacer behind. No such luck:

So at this point I knew the 3rd was being pulled. 30 mins later the 3rd is on the floor and immediately I see the cause of the metal build up in the diff.

This pin has been contacting the pinion gear and wearing down. Everything else looks fine from the outside. Put air to the locker when it was out and verified the locker does not leak air under no load. At this point I am going to go to a solid spacer but the bearings look as new so will leave them. Anyone that's an expert on these lockers, what should I be doing with this unit? Model RD253.

 

[mudgudgeon]

You didn't mess about!

Good to find answers to the problems.

No I idea what your solution is.

 

[Indestructible 47]

You didn't mess about!

Good to find answers to the problems.

No I idea what your solution is.

Thanks mate appreciate it

 

[leonard_nemoy]

If your breathers aren't clogged than the internal air seal is leaking. Time to tear down the diffs and rebuild the locker.

This is happened to me and this is why I will run Eaton e lockers on my next rig.

 

[jonheld]

There's supposed to be a small Allen screw that keeps the cross pin in place.

 

[alia176]

RD253, just contact ARB Aust and ask for their advice, it's that easy. They have rebuild kits (if you need to go that far) and these things are easy to tear apart and rebuild. If you had it installed originally, your paperwork should have an exploded view of the parts diagram. Othewise, ARB can send you the PDFs. They have updated the O rings from round to a square style so be sure update those while you're in there.

Sounds like when the locker is engaged, something is causing the air to escape out of the two O rings, through the axle housing, up the axle vent tube into your nostrills. The big clue for me is that your air comp keeps running and running.

ARB air lockers are awesome and few bad examples don't tarnish the entire product line. Mine has been going fine for 19 years on this rig, and eight years on a previous rig. Some folks mess up the older style O rings and cause their own leaks. Installation error is a big reason why they leak. They simply just don't start to leak randomly unless the copper tubing inside the diff rubbed against the spinning ring gear, which has happened to me. Again, this was an installation error on my part and discovered it on the first outing!

 

[Indestructible 47]

Well, manufactured march 03/2020. Means this bastard is still in warranty. Reckon I'll let the pictures speak for themselves. I'll talk to ARB later today when they open and see what they'll do for me.

 

[baldilocks]

This is no fault of the RD132 unit. The ARB is stupid simple and that’s where durability and reliability stem from.

I recently had to replace a broken ring and pinion up front so I took the liberty of , although not necessary, taking my ARB apart and replaced the bonded seal, clutch gear and return spring. All in just north of $100 and easy to do even for me.

My ARB’s are from 2010, far from the oldest still in service out there, and have been abused time and again never giving me grief, never failing no matter the circumstances or weather conditions.

Before buying an Eaton Harrop e-locker study up on all the monkey motion going on in one of those units.

 

[Indestructible 47]

This is no fault of the RD142 unit. The ARB is stupid simple and that’s where durability and reliability stem from.

I recently had to replace a broken ring and pinion up front so I took the liberty of , although not necessary, taking my ARB apart and replaced the bonded seal, clutch gear and return spring. All in just north of $100 and easy to do even for me.

My ARB’s are from 2010, far from the oldest still in service out there, and have been abused time and again never giving me grief, never failing no matter the circumstances or weather conditions.

Before buying an Eaton Harrop e-locker study up on all the monkey motion going on in one of those units.

I am still a fan of the ARB unit. No question. The seals in my unit aren't leaking at all, this dowl pin has snapped off and sent metal through all the gears wrecking the ID surface that sits on the pins. Given the locker comes assembled from ARB this is a failure on their part, which could of stemmed from a small mistake in assembly. But this unit is now toast, the pin has damaged the carrier surface. Just a 1 in a million type of failures this one I believe.

 

[baldilocks]

Who really knows what someone else may have done to it before you bought it. Maybe ARB can offer some relief.