ARB stops working under stress

Hip · Mar 22, 2016

RD166 dana 60 LP

air system is tight holds air overnight.
Lines dont leak and are not plugged.

when wheels are in the air it works perfect, passes ARB's bench test for in vehicle. appeas to engage and diss engage.

disassembled it and no stripped splines on the axel and no broken axels.

Get it in the snowor any place i need it and it wont lock.....WTF

Took it out of the housing and inspected it. nothing appears to be broken. not one metal flack in the oil. shoot air in the hole and the collar slides and engages....

any ideas or something i can check?

Bobbo3234 · Mar 22, 2016

supplying enough pressure to the diff?

crash2 · Mar 23, 2016

Any idea what the pressure is hippy?

fj401ton · Mar 24, 2016

verify 90 plus psi is getting to the locker,, also verify you have good preload on the carrier bearings, also verify the orings aren't damaged even the slightest. had similar issues and ended being preload and a shitty oring. they ride on a very small surface and when cold the contact area was even smaller.. when it was warm it was never an issue

Hip · Mar 24, 2016

air is supplied by a york using the ARB switch. system is 100 psi.

disassembld the ARB and there is nothing wrong/broken.

i did find a area of the line that was smashed but does not leak and gets plenty of air flow.....gonna replace that and see. its not the plastic its steel braided nylon and pretty tough.

about the preload....its certainly not the tightest carrier ive ever done but i am able to get it in without a case spreader. i dont follow how that could be the issue?

zukkev · Mar 24, 2016

The looseness of the carrier can attribute to the 2 halves of the carrier possibly trying to spread...But the ring gear bolts would have to be loose to have that happen...and I don't think you have loose R.G. bolts, right? I think you are dealing with a pressure/volume issue...Are you using a gauge in the air system, and if so, have you verified its accuracy?

Hip · Mar 24, 2016

no but that is on the agenda for today, gauge and a new line.

fj401ton · Mar 25, 2016

ring gear bolts dont have to be loose if there is higher than 10-12 thou backlash,, the carrier will deflect if no preload on the carrier bearings.

CHOP SHOP · Mar 25, 2016

Yes, carrier deflection can cause the seal to leak. The cap to carrier air connection is extremely sensitive to carrier movement/ lack of preload.

I cant stress enough how important bearing preload is even without an ARB.

crash2 · Mar 25, 2016

Ya those things are VERY critical o0n side bearing preload.

Hip · Mar 25, 2016

so after line change everything works but there is now a leak inside. i got the bulkhead fitting cross threaded and it leaks there. i made some special stuff to eliminate all the cheesy ARB stuff cause at that time i had full machine shop to make ****.

so off to have a new fitting made.....:redneck:

Hip · Apr 27, 2016

Ok made a new fitting out of stainless, last one was brass. Its now tight. Everything works in the yard on my obstacle.

Went to a local comp and sure enough it started failing. After extensive testing i removed the last ARB part, the solenoid appears to fail intermittedly.

So now its comp on arb eng, to unlock turncomp off and release pressure in system with the air chuck.

Looking for the right ball valve with a vent.:redneck: