No end in sight for my ARB for the rear. Mine wont be at super cell.

So earlier this summer, we had a wrench day down at Kinder’s place (thank you). I was able to get the ARB part that was cracked and causing a leak replaced, bench tested, and tested on the Bronco with no leaks.

This last weekend, I took it out for the first time. My first attempt to engage the air locker, it was just an immediate leak in the axle tube escaping through the vent tube.

I’m hoping to pull the differential in the next day or two and see what is going on but I’m quickly growing frustrated with the performance of this 9” ARB.

On another note, I broke the u-joint on the D44 driver axle shaft over the weekend. I ordered some chrome moly shafts with the 760x u-joints so I’ve got some work to do in both axles before SuperCel.


Sent from my iPhone using Tapatalk

I am so sorry about the ARB. I hear about more trouble with them than good things. I attempt to steer anyone away from them.
What I can't understand is that with the 9" being such a popular axle, why aren't there more options for a selectable locker??? Someone needs to make an solid E-locker and they could make a killing!! Offroad to drag cars...

I went Chrom-mo's back in 2012-ish and have yet to break one shaft since. I need to be better at maintenance on them (mine require the needle grease fitting), but they have been super solid!

Yah-- it seems like people either have nothing but bad luck/experiences with the ARB or they seem to never run into issues and love them. The silver lining i guess is that I have probably improved my trail driving and technique a ton because of the unexpected inability to use any lockers.

I did pull it apart and somehow, the set screw that is supposed to be in the air actuator hole on the flange cap is just not there. It had to have been there when we installed it because it worked sitting in the garage. ACE hardware only had as small as 4-40 and I am fairly certain that the ARB would use metric. The 4-40 size did not work.

I ordered a kit off Amazon that has an assortment of M2, M2.5, and M3 set screws so we will try to see if one of them is correct and see if I can install with some red loctite. Ohhh.. also- I called and talked to ARB about it and asked them if they could tell me the size of the set screw and they had no idea and the guy I talked to thought they weren't supposed to come out (meaning they were somehow permanently installed). He told me I could fill out their online form and they could replace the flange cap kit completely and make sure it has a set screw (again-- this one had to have had it since it bench tested fine). I would rather just install a mutha F*$#&'n set screw than have to tear the entire thing down and set up ring and pinion again...

To Be Continured....

Eck,
I could swear that a set screw was installed. Kirk might remember. I remember it working on the bench.

Well-- for reference, the set screw size is 2.5mm. I installed the set screw with loctite and let that dry for about 1.5 hours. Tested it and the result is . It is cracked in the exact same spot the previous one was. Now-- the big difference is that the first time it happened, I had gotten thousands of miles and some actual rear-locking out of it before it failed. This one not only cracked and somehow out the set screw entirely, but I didn't even utilize the rear locker ONE time.

I have submitted a warranty request online and hopefully they will send a replacement quickly. I admit, this has jaded my confidence in ARB and am not sure what else to do other than just get really good at pulling and replacing parts, setting up ring and pinions, wheeling without lockers, and root against Australia in any sporting event!

Geesh! That's not good. Lets see if you have better luck with ARB customer service than I am having with Lenovo computers!

Oof. That sucks. Hope they take care of you.

That seems super weird. I hope they step up and get you new parts.

Could there be something causing that to break? Bent housing? I'm just balling but it seems too coincidental to break like that again. I'd start looking for a root causes before assembling it all again. I did a lot of reading on 9" ARBs before buying mine. Most the systemic failures are with the 35 spline 9" ARBs (what I bought, lol). I never saw any failures like that.

This was ARB's initial response:

I have seen only a couple air journals in almost 20 years where the grub screw was legitimately left out in manufacturing. It certainly isn't common, and it shouldn't happen on a production locker as pressure testing every unit is part of the assembly process at the factory. Further, if the unit bench tested ok, the grub screw could not have been missing at the time of install. Looking at your photos, it appears you may be having contact inside of the bearing journal with your axle shaft. This could certainly cause a scenario in which the journal would develop a hairline fracture along the hole and consequently allow the grub screw to exit.

The axle was also brand new when I installed the original air locker and I do not see any evidence on the axle itself from making contact. I suppose it might not take much contact to create the small cracks that are seen but I am not sure how else to determine root cause. The ARB itself is definitely out of warranty so it would be quite the reinvenstment and leap of faith to replace it with another one. I responded to ARB that I do not see any evidence of the axle making contact so we will see what their response is...

the axle may not be bent but the housing may. That will cause the axle to rub the ARB. you may have to pull it and have it checked.

Sorry to hear of your troubles. FWIW my arb works like a champ. even my front which is OG from the late 80's.

to me you just answered your own question. Tire wear on the back is a good indication of a bent housing. to really check straightness you need bearing plugs and a precision ground bar to go across the axle.

I was looking for a technique for checking housing straightness I read about years ago. I couldn't find it but found a lot of ways to measure and some Youtube videos.

If it's bent, my guess is that it is bent 180* from the axle "scuff" marks inside the locker.

Is the side with the worn tire the side that has the crack on the arb? If you havent rotated tires thats something to think about.

Quick Summary of what I did and found out in the process...

Sent a warranty request to ARB for the flange cap kit with pictures. The communication with them was essentially, they have not seen this issue in the 20 years the service tech had been working for ARB so there must be something else happnening. The suggestion was to check the housing and axles were straight. The axles are newer and looked to be in great condition so I took the housing to a shop to check whether it was straight.

Both sides of the housing were bent a lot. One side was 3/4" and the other was 1/2". So they were able to straighten the housing and I was able to get everything back together in time for SuperCel. I did have to replace the flange cap kit again. Rear Locker worked all week so it appears the bent housing was the cause and am hoping I do not need to deal with the guts of the rear end for a while!

On another note-- I have had a sizable oil leak for a few years now and thought it had to have been leaking from the backside of the lower intake. I removed it and was very meticulous in re-sealing a couple of years ago and it has not solved the issue. The backside of the engine is 10X dirtier than the front half of the engine so I am starting to think it could be the rear main. SO-- my plan is to pull the engine out and clean everything up and reseal EVERYTHING that could leak (oil pan, rear main, lower intake, valve covers). Does anyone have any input I may not be thinking of?

Also-- I know there are engine hoists and stands floating around-- anyone have both I could borrow for a few weeks at some point this fall?

I've got a cherry picker you can use.

Sent from my Pixel 5 using Tapatalk

I just did my rear main seal. I put it off for 20 years because I was intimidated by the process. It turned out pretty damn easy. I'd consider doing it in the truck. Buy 2 rear main seals, they are easy to damage. Use the Fel-Pro one piece oil pan gasket. Look at your dipstick/oil pan seal if you have that style, and address it when the pan is off.

Add a truss/backbone to your axle to prevent it from bending again?

https://www.ruffstuffspecialties.com/9FACTORY.html

Glad you got it sorted out!! Who was the shop that straitened your axle? Others may want that info.

As Gunni said, you may want to look into a truss. Something I would like to add to mine someday too.

I thought the same thing about removing the transmission. Search for Youtube videos and you'll see how easy it is. The rear main is 2 pieces and you only remove the oil pan and rear main bearing cap. I would have done it years ago if I knew you didn't have to remove the transmission.

Mine is a 1989 block. I used the 1 piece rear main.

If you have any doubt of the surface, look at a Speedo Sleeve.

Sent from my Pixel 5 using Tapatalk