Issues with ARB RD89 Locker

[jeverich]

Having some issues with an ARB RD89 that’s installed in my Tacoma 8.4” rear differential. The locker was purchased used, and installed in January 2013. It had been working flawlessly up until about October of 2014.

Here’s what’s going on:

- When the locker is engaged, my compressor CKMA12 (w/ARB solenoid & nylon air line) - will cycle approximately every 5 seconds
- Upon de-pressurizing the locker air line, a puff of gear oil will spray out of the solenoid exhaust port
- I can visibly confirm that air is entering the case by placing a balloon on my differential breather with the locker pressurized
- I’ve confirmed the appropriate amount of gear oil in the differential, so the O-Rings are sitting in an oil bath per ARBs specs.
- It happens irregardless of ambient temperature (Moab and snowy Washington)
- It was pressure tested immediately following installation, and held air without any leaks for 20 minute
- All internal O-Rings were replaced upon installation


All of these symptoms lead me to conclude that an internal O-Ring(s) has failed, causing the locker to pressurize the differential casing, and back flow through the air line…

It's gotten progressively worse, and that gear oil is making a mess when it exhausts out of the solenoid. Truck is still totally drive-able, but I don't like the fact that the integrity and functionality of my locker is completely compromised. Seems as though there were a few problem child RD89s that were known for eating seals constantly. I'm hoping mine isn't a member of the same family... Not opposed at all to replacing the seals myself. I'll just have to pull the third and the carrier.

Anyone else have/had this same issue??

Curt, maybe you'll grace me with your knowledge?

I've sent an email to ARB regarding the issue, we'll see what their response is. Their service is impeccable, and I have the utmost faith that it will continue to be second to none.

Thanks,

jake

 

[cruiseroutfit]

Have you checked your axle vent? Sounds like failed o-rings... either due to some installation error, contamination or other. More of my thoughts:
http://cruiseroutfitters.com/tech_ARB_troubleshoot.html

 

[jeverich]

Have you checked your axle vent? Sounds like failed o-rings... either due to some installation error, contamination or other. More of my thoughts:
http://cruiseroutfitters.com/tech_ARB_troubleshoot.html

- I can visibly confirm that air is entering the case by placing a balloon on my differential breather with the locker pressurized

Thanks for the reply, Kurt. I've been scouring Pirate and TTORA; seems as though ARB acknowledged that there was a high potential for o-ring failure. Looks like they were basically offering two options:

Either install new and re-designed o-rings
Replace your unit with a retrofitted RD89

Either one is an option for me; I'm about 1.5 hours away from their facility in Renton. I'm hoping that they're still prepared to offer support for the 89's; it's replacement came out 8 or so years ago...

They're customer service has been kick *** for everything so far; they overnighted me a cover for my RTT at no cost!

I'll keep this updated.

 

[jsnow]

The RD89 has been replaced by the two piece design RD129. That being said, I'm sure if you bring the locker to Renton they will go through it, and get it working again!

 

[Stoffregen Motorsports]

There are actually 3 seals inside that diff, one main "piston" seal and two o-ring seals in the seal housing on the side. The copper air supply line could also be cracked and the o-ring at the bulkhead fitting could be compromised too. Most likely you have leaky o-ring seals, but it is possible to damage the piston seal. The easiest way to tell is to remove the diff from the axle (carefully so you don't damage the copper air line) and hook the air line back up once the diff is removed and pressurize it. Use some soapy water or windex to find the air leak. Check your air line feed bulkhead before removing the diff.

Luckily it's in the rear axle!!!

 

[BigSwede]

I replaced the O-rings on my Trooper rear axle air locker a couple of years ago...if I can do it you can. Just be careful that you get any shims back where they were when you reassemble.

I had to remove the axle vent valve to stop the gear oil spitting issue, I extended the breather line up along the fuel filler and goosenecked it there.

Luckily it's in the rear axle!!!

True dat!

 

[jeverich]

Thank you for all of the suggestions, I've run through most of them already; although I'll go ahead and inspect the diff this afternoon. Just somewhat of a headache when it's your daily driver...

The fact that I'm in such a close proximity to ARB in Renton makes it a little easier to justify bringing the rig to them for the day...

Maybe they'll bestow a set of their new remote resi's on my truck as a thank you gift?