Tech Tim
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WaterH
Well-known member
Don’t know shit about ARBs, but if you are running portals, they have considerable less stress on them.
welndmn
Well Done Man
All of this increase PSI on an ARB seems like a good youtube video :)
Tech Tim
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Will add that to the growing list!
Sean
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Agreed....and I'm more of a finesse driver, so I think the regular ARBs will be fine for my use. If they're not and they fail in the 5 year warranty from ECGS, I'm hoping I can just pay them extra to upgrade to the comp version. That said, they may not warranty the locker itself for 5 years anyway and it may be just the manufacturer's 1 year (IIRC) warranty.
Regardless, it's not the end of the world if I have to replace a third....but it will violate the buy once, cry once philosophy.....however, it's also about 3X the price. Luckily I only need to buy 2 selectables for the rear of my and my wife's cars. Could be worse....I could be doing ARBs in both ends.
I have the CKMA12 compressor and a Dana 70 ARB and find it stupid as hell that I only have a 70-100 psi switch on the compressor and someone with the same exact locker can have a 135-150 switch on a different compressor and that would change how much pressure is going to the locker. It’s the same company and I’d imagine they would want the same pressure going to it.
Sean
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Probably has to do with the duty cycle ratings of the various compressors. They realize some customers are going to fill tires (or tyres in OZ, lol) with them and they are probably worried about burning them up under warranty. Just a WAG on my part though....
Probably the case, I thought air pressure was extremely important in these things but it’s probably not as important seeing they don’t prioritize it
Tech Tim
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ARB has tested the lockers and they lock in good with 70-100 psi. iirc, many of them lock in with less than that.
My recommendations of 150+ are especially important for the 9" Air Locker due to the shallow lock they have. The big danas have more locking engagement.
BUT, I'd say the 150+ psi recommendation also goes for all Air Lockers for anyone running competitions or to anyone who beats on their junk (like the peeps on IBB
).So I just switch out the pressure switch to 150 on my CKMA12 and it will send the 150 to the locker? I don’t have to make any changes to the solenoid?ARB has tested the lockers and they lock in good with 70-100 psi. iirc, many of them lock in with less than that.
My recommendations of 150+ are especially important for the 9" Air Locker due to the shallow lock they have. The big danas have more locking engagement.
BUT, I'd say the 150+ psi recommendation also goes for all Air Lockers for anyone running competitions or to anyone who beats on their junk (like the peeps on IBB
I am hopeful I have an ARB with long term success.
I broke the old Eaton 2 pin lockers in my sleep. I broke a Dana 44 ox locker (design flaw with 1/4in bolts that back out which ox supposedly fixed later on) I also broke the “new and strong” 4 pin Eaton in my Dana 70 after 5 years of use. I won’t even try an auburn because I know people who broke them that are easy on stuff. I was fearful of ARB air issues but I took my time and tried to perfect the install and its been flawless in operation for a little over a year now.
Rangerrod
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Russell makes fittings for arb bulkhead and solenoid to convert to -3an. I have converted both of my rigs to this and have had zero issues. Maybe Tim has cheaper alternatives.
Tech Tim
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Yes, swap out the pressure switch with a 150 psi switch. The compressor will handle it for running the air lockers, no problem.
The problem would come if you then were running that compressor straight out to fill big tires and overheating things. ARB specs that compressor with a 100 psi switch, jumping up to a 150 and you're pushing it harder.
Many people are scared of the Air Locker because of all the stories of air problems. Size them to your application, install them correctly and keep the oil clean and you should get years of service out of them. I recently rebuilt a 20 year old air locker for a buddy, he had bought it off FB marketplace used, turns out the original owner had me rebuilt it 15 years ago or so and it is still running strong.
Russell makes fittings for arb bulkhead and solenoid to convert to -3an. I have converted both of my rigs to this and have had zero issues. Maybe Tim has cheaper alternatives.
ARB JIC 04 fitting pn# 0740105, just over $6.00 for a pair:
Perfect, I’ll swap it out. All I’m doing is locker engagement. I have a home built powertank knock off for filling tires. If I use the CKMA12 for filling tires shit hit the fan and it’s probably once in a lifetime thing.
I agree on quality of install. I bought the test tool where I set it to 100 psi and I think spec is no leak for 2 minutes or something. I made sure I had no bleed off for 5 min. It’s been flawless. I’ve contemplated ditching the plastic line and doing the 3an lines.
I agree on quality of install. I bought the test tool where I set it to 100 psi and I think spec is no leak for 2 minutes or something. I made sure I had no bleed off for 5 min. It’s been flawless. I’ve contemplated ditching the plastic line and doing the 3an lines.
Sean
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Russell makes fittings for arb bulkhead and solenoid to convert to -3an. I have converted both of my rigs to this and have had zero issues. Maybe Tim has cheaper alternatives.
That's what I did too...along with air switches for engagement. Been running various ARBs for 27 years now....only had 2 failures...neither was the ARB's fault. The first was before I welded and my weldor accidentally welded too close to the blue plastic airline (switched to SS braided -3 after that never had an issue again), got the metal around it hot and it melted. The 2nd was when a shop arc'd through the compressor and burned it up.
'84 Bronco II
El Chingón
I assume you are talking about the ECTED design that is currently branded as the Select-A-Loc Limited slip to Lock? Those are well known garbage.
I am curious about the new open to lock version they came out with recently. Looks like a good design and Tony Peligrino supposedly ran them in his 4400 JK.
white-rhino
Older than dirt
OK, so here is an ARB failure - sorta. Mid 2000's I had an ARB front/rear in a set of Early Bronco axles. Wheeling in Canada 'nord of da Soo eh' and I started blowing dif oil out of the vent tube on the rear 9". Get back to camp, have dinner, sitting around the bonfire drinking some beers and my buddy says, "you know, we can either sit here and talk about what it might be or take it apart and find out".
So, put it up on the trailer deck, park vehicles around with headlights and tear it down. And we found...........
Back in the early days, ARB's had an internal spring loaded check valve/release that would dump air inside the dif when it was turned off vs pushing air all the way back to the solenoid under the hood. The check valve was stuck open with a little critter. Like a little bug with legs.
Since this is a closed cavity, the only idea we came up with, was that during assembly, late at night, bugs flying around, one got in side somewhere somehow. 
Mind you, this dif had been running fine for quite some time. It wasn't like it was a fresh build. Mystery to this day........
So, put it up on the trailer deck, park vehicles around with headlights and tear it down. And we found...........
Back in the early days, ARB's had an internal spring loaded check valve/release that would dump air inside the dif when it was turned off vs pushing air all the way back to the solenoid under the hood. The check valve was stuck open with a little critter. Like a little bug with legs.
Since this is a closed cavity, the only idea we came up with, was that during assembly, late at night, bugs flying around, one got in side somewhere somehow. Mind you, this dif had been running fine for quite some time. It wasn't like it was a fresh build. Mystery to this day........
AgitatedPancake
Frobot
So I just took apart a used RD99 I picked up a while ago, glad I did. This is the first one I've actually taken apart and measured engagement for myself.
These ARBs use a locking collar to grab teeth around the OD of one spider gear:
The maximum engagement depth is from the back face of the spider down to the top of a pinion tooth:
Which on this locker, is only .125". And that's not accounting for the fact that the locking collar doesn't seem to rest on the pinion at full lock (so there's some sort of air gap), and that there are ramps on the lock collar teeth
Even though these ramps look pretty uniform around both sides of each tooth, I'm thinking these are significantly rounded out more than stock. Because with them, the engagement numbers are crazy low. Does anyone have a picture of what brand new lock collar teeth look like?
Because those ramps take away from the .125" max engagement distance on top of the seming air gap at full engagement. I wouldn't be surprised if this locker only has like .060-.070 functional engagement not even counting any potential deflection under load.
These ARBs use a locking collar to grab teeth around the OD of one spider gear:
The maximum engagement depth is from the back face of the spider down to the top of a pinion tooth:
Which on this locker, is only .125"
. And that's not accounting for the fact that the locking collar doesn't seem to rest on the pinion at full lock (so there's some sort of air gap), and that there are ramps on the lock collar teethEven though these ramps look pretty uniform around both sides of each tooth, I'm thinking these are significantly rounded out more than stock. Because with them, the engagement numbers are crazy low. Does anyone have a picture of what brand new lock collar teeth look like?
Because those ramps take away from the .125" max engagement distance on top of the seming air gap at full engagement. I wouldn't be surprised if this locker only has like .060-.070 functional engagement not even counting any potential deflection under load.
Sean
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With that kind of issue being apparent, why doesn't ARB just make the 'comp' version the standard one? It's already engineered, they clearly realize it's a problem.....seems at the very least ethically questionable to continue to offer the subpar product.So I just took apart a used RD99 I picked up a while ago, glad I did. This is the first one I've actually taken apart and measured engagement for myself.
These ARBs use a locking collar to grab teeth around the OD of one spider gear:
The maximum engagement depth is from the back face of the spider down to the top of a pinion tooth:
Which on this locker, is only .125"
Even though these ramps look pretty uniform around both sides of each tooth, I'm thinking these are significantly rounded out more than stock. Because with them, the engagement numbers are crazy low. Does anyone have a picture of what brand new lock collar teeth look like?
Because those ramps take away from the .125" max engagement distance on top of the seming air gap at full engagement. I wouldn't be surprised if this locker only has like .060-.070 functional engagement not even counting any potential deflection under load.
Granted, I don't know if there's a significant redesign that increased the engagement or if it's all better materials driving the 3X increase in cost....but it just seems like ARB should fix the clearly known issue and discontinue the older design.
EDIT Some companies selling the comp version are claiming 290% increase in case strength (not necessarily anything to do with locking collar engagement.....JFYI.)
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AgitatedPancake
Frobot
I feel like I heard that the comp cases are cut out of tool steel, but I don't know if that's where all of the strength increase came from or if they made geometry changes to the exterior as well. I'm really curious of the comps are geometrically different internally too like having a different lock collar/engagement depth etc.
So I just looked up the part number for this lock collar (ARB 050904), and it also cross references to their RD116 and RD117 Dana 44 lockers which kinda makes sense with the sizing. That also helped me find out they're relatively cheap ($78), and are not supposed to have the ramps. So new collars are happening for sure. These particular ones of mine also have damaged air seal surfaces, so I might be getting new end caps as well. Gotta pay to play I suppose
Internet:
Mine:
Tech Tim
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Even though these ramps look pretty uniform around both sides of each tooth, I'm thinking these are significantly rounded out more than stock. Because with them, the engagement numbers are crazy low. Does anyone have a picture of what brand new lock collar teeth look like?
Because those ramps take away from the .125" max engagement distance on top of the seming air gap at full engagement. I wouldn't be surprised if this locker only has like .060-.070 functional engagement not even counting any potential deflection under load.
You are interpreting it wrong, those aren't ramps.....That is the engagement that has chipped away and now that locker won't stay locked even with 300psi of air pressure.
The teeth should be square.
AgitatedPancake
Frobot
I'm definitely seeing it now, I'm surprised at how...uniformly the metal smeared. Caught me off guard initially haha, but that would explain why the previous owner was just over it with these things. Do you happen to recall who did the batches of these rings in 300m (or some other harder material)?
YotaAtieToo
Thick skull
It's also interesting that they're uniform in both directions. Seems unlikely that you would engage equal amounts of time in reverse as forward. Unless I'm misunderstanding how those ramps formed.
Make sure you price out all your needed parts before you start. Last year I spent $800 rebuilding a $300 arb that cost $1050 new.
Tech Tim
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Spidertrax used to make them and I had a guy down in AZ make up a bunch for me that I sold on the old board. Unfortunately I don't have any more left.
It's also interesting that they're uniform in both directions. Seems unlikely that you would engage equal amounts of time in reverse as forward. Unless I'm misunderstanding how those ramps formed.
Make sure you price out all your needed parts before you start. Last year I spent $800 rebuilding a $300 arb that cost $1050 new.
It is crash locking that causes that and often from someone crimping down that soft copper line too much. They get up to an obstacle, driver hits the button, the locker is slow to engage and the driver is on the go pedal before the locker is fully locked in. They start out chipping just a little and it gets worse as it gets through the hardening on the outside.
AgitatedPancake, Do you have the air collar with that locker? what does the bulkhead end look like?
This was one of the things that got us playing with higher and higher pressures trying to get them to lock in fast and stay locked in.
It was our awesome catalog team that added it, I just put a request in.
YotaAtieToo
Thick skull
It's funny that another of people like to stop to engage their locker, shift into 4hi, ect. I've always found that doing it while rolling at slow speeds works better especially turning slightly.
AgitatedPancake
Frobot
Awesome that you and Spidertrax made a few batches of them! I may have to ask them if they still have the drawings and if they have interest in doing a small run of them.
Funny enough I was just digging through the parts I got with them looking for the air collars and found the previous owner gave me a spare lock collar, win.
I have one of the air collars, and I find your statement on locking delay very intriguing, this one was definitely overcompressed and heavily restricted flow through the ID.
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AgitatedPancake
Frobot
I figured this is the best thread to dump more somewhat relevant observation - decided to split the second locker tonight and compare both side by side, along with the new unused lock collar. The locker from the previous pics is the one on the left.
The brand new collar in the center:
Left lock collar, slipped/smeared in both directions
Right lock collar: slipped hard in only one direction
Unused lock collar: sharp corners in both directions:
The brand new collar in the center:
Left lock collar, slipped/smeared in both directions
Right lock collar: slipped hard in only one direction
Unused lock collar: sharp corners in both directions:
Sean
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I'm beginning to think this issue is why they stop before engaging (never heard of shifting into 4H though)....at least on the 9" version. I guess I've always either been off the throttle completely, barely moving or stopped when I've engaged mine....but I've never had a 9" ARB either....mine have all been Toyota 3rds and D60s.
So looking around, now that Yukon no longer makes a Zip for the 35 spline 9".....it doesn't seem like there are any other selectable options out there other than ARB.
Beginning to wonder if I should just go with a spool in the rear too (portals/4wheel steer).
I wanted the selectable in the rear to be able to more effectively use the rear cutting brakes.
A Grizzly is another option, though my understanding is if I'm still in rear drive in the tcase, and I'm on the gas at all....the axles are effectively locked together anyway.
I wonder if I'm in front drive only how an autolocker like a Grizzly would react to handbraking one wheel if it was installed in that rear axle?
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