ARB Air Locker pumps oil (1 Viewer)

[willie]

I'd like any advice on this the board can provide.

I had a shop install 4.88 gears and ARB air lockers front and rear for my '97 FZJ80. I took the 3rd members to them for the work and I did the remainder of the work. Everything works well with one exception...

I first noticed it after I reinstalled the 3rd member and before plumbing the air line or actuator. After driving at highway speed the rear unit pumps a small amount of oil out of the air fitting on the 3rd member casting (enough to fill the cup of your hand). It does this after a drive at 60+ mph once it's parked. I don't think it's pumping oil while driving because I don't find oil blown around the rear end of the truck - only after parking.

I've checked the rear axle vent thinking it was blocked and allowing air pressure to force the oil out. Not so. The air line is fully open and I can blow compressed air in through the axle fill plug and it blows out the vent. No restriction.

I've since plumbed the air line. The ARB engages and disengages just fine. There are no air leaks into the rear diff from the pump when it's engaged. I thought maybe the air ring actuator was torn and allowing oil to be pumped out there. Not so. It's working fine.

It took the truck back to the shop that did the 3rd member work and they are talking with ARB. No answer from them so far. Another shop in the area said they had a similar issue with ARB air lockers with 4.88's. Something about the gear ratio and locker combo in late model FZJ80.

ARB apparently has some sort of pressure release valve to install inline near the rear 3rd member that in someway addresses this. Although I don't have the details on this yet.

Any ideas out there? I'd appreciate to know if anyone else has this gear ratio and ARB air locker combo in a late model 80 with simialr problems? Or any ideas for troubleshooting?

Thanks for your help!

 

[tarbe]

I had this same problem after I put 4.88s and ARB lockers into my FJ40. Never did figure out how to stop it...sounds like maybe yours is more severe than mine. I'd just get some spray on the fenderwell from the air compressor.

I sold it a year after the lockers were installed, so sorry I don't have advice...I thought you might like to know this is not an unheard of issue.

 

[Arya Ebrahimi]

Hmm, I was gonna suggest the blocked vent when I started reading, but now I'm puzzled as well. Definately keep us updated as things progress. Good luck

Ary

 

[LandCruiserPhil]

Bad O-rings (2) on the air locker collar. Mostly caused from misalignment of the collar during installation.

 

[willie]

Well thanks for the inputs.

I've tried all the basics. I think the o-rings are the likey culprit as suggested. Although if this was the case - I thought it would leak air and the pump would come on periodically. But it holds air fine and engages with no trouble. So I'm not sure, but I think you guys are right it's the only explanantion for allowing oil into the air line.

I'm going to try to contact ARB and see what they say. I'll reply back once I get the fix.

THANKS!

 

[robbie]

If the orings were the culprit, you would also get air into the diff. many of the older diffs have the internal u-shaped pressure ring to acutate the lock. the newer style is what I call a quad oring (double lip o-ring, two lips inside and two outside). Any how this will usually take care of these pumping oil issues s well as intermintent air leak into the housing. What happens with the older style u-shaped one is that debre can get stuck under the lip a allow the oil then to be pumped back up through the air line. christo had a quite a time with this on the front diff. I really do not think you will find the 2 orings not sealing with low pressure and pumping in the carrier area, unless you have air escaping into the axle under lock pressure. good luck with ARB doing anything on this.
later robbie

 

[willie]

Robbie,

Thanks for the information. I neglected to say but this is a new locker. I don't know what style o-rings it has. I assume it's the latest. Either way, what you describe could be the problem. The shop could have gotten some dirt or metal into the seal housing when it was installed.

I called ARB Australia last night - I thought I'd get the straight scoop. They think that the seal housing may be defective and gave info on how to check it. I went to the shop this morning and they're taking the 3rd member out for inspection. ARB said they would replace the parts or the whole unit if it's determined to be the problem.

So at least I have the shop and ARB working together to solve the problem. Both of them have been good to deal with so far. I just think the problem has them a bit stumped.

The worst part is that I've been with the truck now for almost 2 weeks. And likely not to hav it back this week if they have to start shipping the unit back to ARB for warranty replacement..... oh well.... life's little problems....

Once we find the source of the problem - i hope this week - I'll post the fix here. Maybe it will save someone else some troubleshooting time.

Thanks everyone for the help!

Ernie

 

[sleeoffroad]

As Robbie mentioned my old truck did that. I would drive down the road and it would pump oil all the way up and out of the solenoid. Locker worked when when used. It would not do it on the trail. Only at high speed driving.

ARB kept on saying breather blocked. I ended up drilling a new 3/8" breather with a open hose to the engine bay and it still did it. It was only after we installed the new seal that it stopped.

It got so bad, that I installed valves in the solenoid lines so that I could shut if off when on the road.

 

[willie]

Christo,

The symptoms you describe are EXACTLY as I have on the rear.

The shop I'm using also recommended adding a second breather line. The owner was calling other shops in the area looking for advice and this was one of the ideas he came across. Apparently some models of the front axle housing have a baffle of some sort that can spearate the housing and restrict venting. No one seems to know if the rear housing is the same design or not.

I've now got ARB directly involved to help. I'll let you know what I find out in this next round of troubleshooting. If it solves the problem maybe it can be applied to your situation too.

Ernie

 

[willie]

We took the 3rd member out this morning at the shop. The seals and seal housing "look" okay - ie. no apparent debris or wear. I have to say they don't appear damaged.

We called ARB US and they asked for the whole unit to be returned for inspection. Shipped it this morning via ground - air freight would have cost me as much as a new locker...

So I won't have any word until the end of the week at best. We'll see what they say from there.

 

[willie]

I promised to provide a closing note on this problem when a solution was found.
Well I've had the truck on the road for about a week and.... It works!

The fix...

The ARB locker was ultimately shipped to ARB USA in Seattle. They disassembled the unit and found "the internal seal to be undersized". I don't have a detailed exploded view of the ARB unit, so it's hard for me to tell what this actually means.

I learned a few things;
1) It is normal for some oil to expelled when the diff fluid heats and can mist in the differential. In this case, when the locker is actuated and released, some of the oil escapes into the air feed line. A normal "mist" of oil. This was not my case.
2) Normal cause of the leak I was experiencing is the outer seals (2) or the seal housing they ride in. This was not my case. These were both in good shape.
3) There is a second set of "inner seals" that are part of the assembly as it comes from ARB. These are not touched during installation process. And I don't think they are visible and cannot be inspected without fully disassembling the carrier unit. In my case, these were "under sized" according to ARB. I don't know what that means but that was the technical write up that came back from ARB. Not very descriptive.

So bottom line... it was a manufacturing defect. I've not heard of this problem before so I don't think it's a widespread problem. And best of all it FIXED!

I appreciate all the input I got back and as usual this is a great source of help!

Ernie

 

[White Shark]

Same problem here, but with the front diff pumping lots of oil out of the solenoid. Installed a few months ago, probably the same manufacturing batch. We'll see... It's coming out of the axle assembly this week or next.

 

[noocroozer450]

I promised to provide a closing note on this problem when a solution was found.
Well I've had the truck on the road for about a week and.... It works!

The fix...

The ARB locker was ultimately shipped to ARB USA in Seattle. They disassembled the unit and found "the internal seal to be undersized". I don't have a detailed exploded view of the ARB unit, so it's hard for me to tell what this actually means.

I learned a few things;
1) It is normal for some oil to expelled when the diff fluid heats and can mist in the differential. In this case, when the locker is actuated and released, some of the oil escapes into the air feed line. A normal "mist" of oil. This was not my case.
2) Normal cause of the leak I was experiencing is the outer seals (2) or the seal housing they ride in. This was not my case. These were both in good shape.
3) There is a second set of "inner seals" that are part of the assembly as it comes from ARB. These are not touched during installation process. And I don't think they are visible and cannot be inspected without fully disassembling the carrier unit. In my case, these were "under sized" according to ARB. I don't know what that means but that was the technical write up that came back from ARB. Not very descriptive.

So bottom line... it was a manufacturing defect. I've not heard of this problem before so I don't think it's a widespread problem. And best of all it FIXED!

I appreciate all the input I got back and as usual this is a great source of help!

Ernie

I'm having the same problem with the oil coming up through the rear diff air line and out the solenoid. Which part/assembly did you send back to ARB? Does it have a specific name?

 

[pappy]

Same problem here, but with the front diff pumping lots of oil out of the solenoid. Installed a few months ago, probably the same manufacturing batch. We'll see... It's coming out of the axle assembly this week or next.

Interesting. Same problem with a new locker in a mini-truck. Guess I'll call ARB.