FZJ80 ARB rear AirLocker home install write-up. (no re-gearing) (1 Viewer)

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Hello world!

So I've kind of been working on my 80 for a few years now and finally decided I wanted to add lockers. My truck was factory unlocked and I had actually purchased a front and rear ARB setup 2 years ago, but I've been too chicken to dive into doing the install myself. My 80 is actually my daily driver, but to be honest, I really have it because I like doing the wrenching and love the endless little fix-it projects. I ride a bike to work about half the time and so it's not CRITICAL for me to get a weekend project wrapped up by Monday morning.... So even though I know I could have packed up the diff and brought it to somebody I wanted to learn learn more about how differentials are setup and I had a great time. Also I'm often skeptical about the care and consideration for a job done by people I don't know, so I sometimes figure that even if I make mistakes at least I'll know what the mistakes are and fix or live with them. I decided to start with the rear because at least pulling the axles is easy.

Anyway, I thought others who might be considering whether they'd like to take on this job could be interested in my experience, including what I thought was really important and mistakes that I feel I made.

My mechanical experience: I always change my own oil, could figure out installing a new distributor and setting timing, but would not consider taking apart a transmission. Messing with a differential felt like a stretch for me because they seem like voodoo magic. Also, I am not a driveline specialist, so I'm just sharing how this went for me and my own ideas and as such would welcome any further insights or corrections from those with more experience.

Tools I have or bought: Basic ratchets and screwdrivers and hammers, torque wrench, impact driver (handy), brass drift (had to buy this, wish I had gone with a smaller one or just bought 2), dial indicator (MANDATORY - I already had one for doing brake runout), center punch, step drill (this works really well for getting through the housing).... I'll add to this list as I think of things.

Tools that would have been nice to have (but I got along without): pressure tester to be sure of no leaks in the system before re-installing in the axle housing. (ARB makes one or you could make one up with a pressure gauge and a valve and some fittings), Arbor press or at least the right size ring for the 50mm bearing on either side of the carrier - I didn't have a socket that was thin-walled enough for this job, a giant vice to hold the carrier while you torque the ring gear bolts, SST for turning the carrier bearing adjusters - as you'll see I made one, but it was totally janky (although it worked)....

References:
ARB RD142 install instructions
FZJ80 FSM - I don't have the link, but I got it off Mud several years ago
Youtube: (these are for an FJ40 install, but seem to be VERY similar to what 80's call for)
ARB air locker install part 1
ARB air locker install part 2

I spent a fair amount of time before diving into this project trying to understand some of the details of Toyota differentials and the ARB system. I think it's useful to know the principles of what you're trying to do before diving in... so if you're not solid on diff's here's some of what I learned before hand and through doing...


- "Carrier" - this is the thing that the ring gear is attached to and that the axles slot into. It's what houses the spider gears and side gears in an open diff or ARB parts or LSD or whatever you have in there and does the actual differential-ing. When you put in ARB lockers you're replacing the stock carrier with a whole new one that's apparently stronger in addition to the locking magic.
- Carrier bearings - The carrier has a tapered roller bearing pressed on both sides to locate it laterally. Like most bearings they need to have some preload so they're not too tight and not too sloppy. Toyota uses a pillow block on either side of the carrier to hold the bearings, but with the addition of these big threaded rings that squeeze the whole carrier/bearing assembly to achieve the proper bearing preload. You also use them to adjust backlash.
- Backlash - these is basically how 'tight' the ring gear and pinion gear engage. You need to have a little bit of slack between the gears for things to run right. (I have no idea why, it's just what FSM and everybody else says). You check this by rocking the ring gear back and forth and it makes a little knock as it bumps into the pinion gear teeth 'ahead' and 'behind' of where your ring gear is meshing. You use a dial indicator to measure how much slop there is. If you move the whole carrier/ring gear/bearing assembly closer to the pinion then backlash decreases and vice versa. This is done with the threaders mentioned above... You just tighten one side by whatever amount and then loosen the other side by that same amount and the preload stays the same, but the backlash changes.
- Pinion issues - If you regear then your ring gear will be larger or smaller and so you'd need to change the "pinion insertion" meaning how far into the diff the pinion plunges. But this opens a can of worms because then you have to make sure your engagement pattern is right (painting on the gear marking compound) AND get the pinion bearing preload right (I believe this is where crush sleeves or shim stacks come into play). As I understand it, if you don't regear you don't really need to mess with any of this, which is why I just left that whole part alone and I'm only planning on ever running 33's anyway. I hope that bearing is still good.....
- 3rd member - this is a 'style' of differential that Toyota uses where the pinion and carrier and bearings and front part of the axle housing all come out together as a unit. It seems way easier than the alternative in domestic axles that require you to assemble and check all this stuff while working in the back of the axle.... I'd seriously just take the whole axle off if that were the case because there is a LOT of rechecking, at least for me.

OK, enough preamble, let's get to the good stuff!

Step 1: Drain diff fluid - capacity is 3.25 L so plan accordingly. Also this stuff smells bad.

Step 2: Pull the axles. Hint from FSM - use a few stiff hammer blows to the center of the end of the axle with a brass drift to pop out the little cone nuts.... also works to bang around the circumference of the hub with a hammer, but the brass drift is probably nicer.... Also even if you already drained the oil there will be MORE that barfs out of the ends of the hubs, so maybe have 2 more catch pans handy or rags or something.
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OK, so I actually haven't posted a build thread or really anything with a lot of pictures yet, so I'm not sure if I'll even do this right.... so let's start off with one of my helper.... (hey that worked!!)
 
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Step 3: Pull the 3rd member. Leave transmission in neutral so you can turn the driveshaft easily to get all 4 bolts out. FSM says to matchmark the driveshaft and pinion flange but I didn't read that part before hand.... no weird vibrations so far, but I would have done that if I had read that part more carefully. Also, This thing is ~80 lbs, so be careful. I just had a floor jack but it has a fairly large cup (or whatever it's called) on the end, so it worked OK, but definitely 2 people is helpful here just to stabilize that thing on the way down.

And here's the stock 3rd member on the benchtop..... You can see one of the adjuster rings on the right side with all the holes all around it and there's a locking tab that keeps it from backing out that screws onto the top of the pillow block.

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Step 4: Measure existing backlash - use a dial indicator (your holder may vary). Spec is .006" to .008"

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You're supposed to measure it in several spots around the gear and take the average. I'd add that it might be good to measure the runout on the back of the ring gear so you have an idea if it was out of spec when you took it out in the first place... mine has something like .006" runout (which can cause some problems with dialing the backlash on the install end of the project) and is supposed to only have max .003" but I don't know if that was already that way or was from me banging on the thing a lot. Either way I left it and we'll just have to see if anything bad happens.

Step 5: Remove the carrier. Take the 2 big bearing cap bolts and the adjuster ring lock off the top of the bearing caps and the whole carrier will just drop right out. The FSM or ARB manual (can't remember which) says to make unique punch marks on each cap before disassembly so you don't mix up which cap goes to which side because the threading obviously would be messed up if you switched them and that would be a bad day if you dinged up the threads on your case. I noticed that mine had 2 different numbers for each cap so I just took a few pictures and nothing got messed up.

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Old carrier with ring gear still on and new carrier

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Step 6: Get the ring gear off the carrier.

Sub step A - take the side gears and spider gears out of the center of the carrier first because the ring gear LOOKS like it will slide off the around itcarrier, but in my case it didn't clear the nubby end of the cross pin that barely sticks out of the side of the carrier and then I had to bang the ring gear back into place enough to allow me to pull out the cross-pin and that was a lot of banging that worried me. There's basically one bolt that frees up the big cross pin (it's pretty obvious on the carrier), tap it out, and then pieces will start falling out of the carrier.

Sub step B - Remove the 10 or 12 bolts that hold the ring gear on. Take a picture or two (I didn't, though) of how they are oriented so you can put the weird bevel the right way when you reassemble. It was a lot easier for me to get these ring gear bolts off because the stock carrier is flat on the sides and small enough to fit in a not monstrous sized vice like a lot of people have on their workshop bench. New carrier, not so much.....

Sub step C - bang like crazy on ring gear to get it off. I had read multiple places that you don't want to do this with a hard punch or a bare hammer as the ring gear is hardened and could crack.... I found a brass drift at Napa and just kinda worked at it in a star pattern and it eventually came off.


(to be continued tomorrow).
 
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Great write-up so far. You pulled the axles/differential out in the street!? That's awesome. You probably had to wait until no one was coming to pull the driver's side axle!! :)
 
Nice Write-Up! You literally can not take too many pictures when trying to show what and how you completed.
Another good source with tons of good pics:
Toyota Gear Installs
 
Great write-up so far. You pulled the axles/differential out in the street!? That's awesome. You probably had to wait until no one was coming to pull the driver's side axle!! :)

Hehe, yeah. I would have preferred to do it in the garage, but we have a movie projector in there and the kids wanted to have friends over so I got booted. We live in a smallish cul de sac so traffic wasn't that big of a deal but people in my neighborhood don't really drive cars more than 10 years old and certainly don't leave them up on jack stands in the street for a few days so I know my wife was dying inside a little bit (devil horns).
 
Step 7 - Transfer the ring gear to the new carrier.

The ring gear fits onto a shoulder and is a press fit, so it's helpful to heat the gear up in the oven or in a hot water bath. I used one of my wife's saucepans while she wasn't home and it worked fine. I like the boiling water thing because the gear oil STINKS and I didn't want that to volatilize in my house and also because with the boiling water it won't get more than 212F. Anyway, do whatever, but ARB warns not to use a flame as that can damage the heat treating or warp it.

Something I missed, I think you're supposed to dry the ring gear (I did this), but then also regrease the shoulder where it will press onto the carrier "so that it won't seize on there". Well, I forgot to do that, but I don't want to have to be back in there again for a long time anyway and it's an interference fit already, so I don't think it mattered that much.

What does matter is getting the bolt holes to match up so you don't have to bang it off again and do it all over. My experience is that even when heated the ring gear does NOT just drop onto the shoulder and still requires some "persuasion" with the drift. I did so with a bunch of bolts through their respective holes so that it would stay aligned as I drove it into place. Seemed to work OK.

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Step 8 - Torque the ring bolts on.

This turns out to be a bit tricky. The stock carrier can fit into a kind of standard sized bench vice to loosen the bolts, but the ARB is too big. The YouTube video guy has a REALLY big vice that he could chuck the thing up in and the ARB manual figure shows a 3 or 4-jaw lathe chuck being used, but I don't have either so I had to improvise. Also, the torque is 81 ft-lbs, so there's no way you could just use your foot to brace it. Here's what I came up with:

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The thing really wanted to twist and turn a bit, but I was able to muster 80 ft-lbs so it worked ok. I used lag bolts in 2 of the bolt holes, which got me 10 of the bolts to torque, then I took out one more of the lag bolts and just let the ring gear wedge up against the cross board on the side.... and for the last one - I just put plenty of Loc-Tite Red on it and laid into it with my electric impact driver and left it alone. The spec on my impact driver was supposedly about 100 ft-lbs, but I don't think it's putting that much out, each prior bolt was needing about 1/4 turn more to get to spec, but 11 out of 12 seems like it's probably fine and with the Loc-Tite it won't back out, so good enough.

Step 9 - press on the carrier bearings. The bearing number is Timken 32010-X, 50mm ID. This is something I wish I'd done differently, but I was on a time schedule so I did what I could.

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So yeah, I used a punch to put both bearings on. Slowly working my way around the inner bearing race. The bearing shown above is the hard one. As you can see the rim to drive against is quite narrow and the cage for the roller bearings sits higher than that rim. Furthermore it's not totally obvious from this picture but you have to press it about an inch past the end of the carrier shaft. And that surface of the carrier shaft is going to have 2 critical rubber seals running on it constantly (the ones that allow the air locking to actually happen), so you REALLY don't want to mar that surface. Well despite my best efforts I got a few very small knicks on that surface. I did my best to feel if there was any lip protruding from the small divots and even ran some 800grit and then 1500 grit sandpaper over the surface to try and hone it a bit... everything seemed to lock in the end under pressure but I have some longer term concerns about this sealing surface, now. I don't think one could find a socket that would work in this situation because the walls of all my sockets that size would have contacted either the cage or the surface of the carrier shaft. You'd need to find or fabricate a ring of JUST the right width and ID/OD to allow you to press it into place. The other side was easy... I think you could probably use a socket and it just goes to a bit past flush with the end of the carrier shaft and no sealing surface to protect.

OK would have liked to write up more, but had to change wifey's oil on her car...... maybe a bit more tomorrow.
 
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Good to see this. I have found that using a combination of old bearings and races typically gets me to the size I need to press anything on. You'll eventually have a collection of these once you do more gear and knuckle jobs :)
 
Step 9.5 - Drill and tap the hole in the housing (or bulkhead as it's called in the ARB manual).

This is actually relatively easy. Just follow the ARB directions - they have a good illustration of where it ought to go. I did go check the housing under my car, though, just to be sure that I was remembering how the 3rd member is oriented when it goes back so as to avoid having to plug a hole drilled in the wrong location. You also want to do this before mounting the carrier so as to avoid any risk of chips getting into your fancy new locker.

Centerpunch so you're drill doesn't wander. I found that a step drill was way easier to use than traditional drill bits used sequentially once I got an initial pilot hole through the cast iron. Didn't even need that much cutting oil. Final drill size is 7/16" and the tap is 1/4 NPT" - the tap actually came with a drill, so that was nice, and I used it to finish the hole to the proper constant diameter once the step drill was to the right diameter on the outside.

For the tapping part I just used a crescent wrench carefully and it worked OK. Lots of 3-in-1 oil (I don't stock Tap Magic at home) and I covered the pinion bearing inside the housing and did most of the cutting with the housing facing down so any chips would fall out of it. Lots of trying in of the 'bulkhead adapter' to make sure I didn't cut the pipe threads too deep/wide, which I almost did....

Then when you're happy there you can go ahead and glue it in with Red Loctite and that job is done...

Step 10 - mount the carrier and get your carrier bearing preload and backlash correct.

This is what took me the most amount of time. Mostly because I originally did it all with the carrier side adjuster put in backwards..... Aarrgghhh!!!

Picture below is wrong

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Picture below is correct:

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Pinion side adjuster for reference, pictured below:

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In my defense the ARB manual doesn't really illustrate which way it goes and I thought I'd need more clearance for the air housing seal (more info on that later). Turns out putting the adjuster ring in backwards makes the backlash harder to adjust too... I think the fingers of the adjuster might have been dragging on the actual bearing cage or something.... Anyway, all's well that ends well.

As you may be able to notice, the adjuster pictured above is a replacement for the stock one. it's fine to use the original on the pinion side. What took me basically the longest was getting a little screwed up from the YouTube videos I linked above. I'm super appreciative of the videos in general, but I don't think he really addresses bearing preload at all. The FSM gives great info, which I'll summarize here, but you basically HAVE to use a SST to tighten the adjusters. I think that bearing preload is something you could probably just do by feel with some experience, which is what I think Bronco92 was doing in the video, but having zero experience I would have likely left the bearing too loose.

Sub step A: Just get the bearings in and get the adjusters just snugged up by hand so the carrier isn't totally flopping around. The video guy puts the bearings in AND the adjuster rings in without the pillow block caps on which I think is a good idea, just to be able to visually count threads on both sides of the adjuster and make sure you're not possibly cross threaded... (the pitch on these threads is fairly fine given their diameter) then he puts the caps on and you want to just lightly snug them down, make sure everything still turns nice and passively. Full torque on the caps makes the adjusters hard to turn. You should be able to just turn them by hand at this point.

Sub step B: Adjust the position of the carrier so that you get .008" backlash. The ring gear side adjuster is the one that affects backlash and the pinion side just preloads the carrier bearings. This is an initial rough adjustment, and then just make sure the pinion side adjuster is hand snugged up.

Here's a photo of how I oriented the dial indicator to measure preload (not touching the gear in this particular photo, but you get the idea). I wasn't totally positive on the exact orientation/angle I should use so maybe others with more experience could chime in here.

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Sub step C: Find zero preload and then go a LITTLE BIT further to put the final preload on the carrier bearings.

(Looks like I'm going to need another post to fit the next set of pictures in....)
 
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THIS IS HOW DIY's SHOULD BE WRITTEN!!! I have been contemplating an ARB locker install and this thread has provided me the information I need to feel confident I can handle it. I'm still going to wait until the thread is complete, but thank you for the time you have put into sharing this with everyone.
1) Clear, focused, well lit images
2) Detailed description of each step (including where you got stuck, mistakes you made, and areas for improvement)
3) Steps and sub-steps to keep things in order and manageable for anyone following along.
4) Light humor thrown in to make reading it enjoyable.

A+ work dude

If you're ever in Cincinnati... Beers are on me.
 
OK, continuation of Sub Step C: Find zero preload and then go a BIT further to put the final preload on the carrier bearings.

FSM directions on how to determine the 'zero preload' point (and then on to proper preload) are actually pretty simple. You torque one bearing adjuster while watching a dial indicator on the opposite adjuster. When you see it start to move, that's your zero point. Here's a picture: (ignore that the adjuster is in backwards..... sigh)

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This zero point is NOT very tight, like you probably could get there almost by hand.

OK, so this particular step took me a while.... I was basically going around and around in circles because the guy in the video was doing something different than the FSM. And I couldn't follow the FSM because I don't have an SST to gradually turn those adjusters. The dude in the video was using a hammer and screwdriver to spin them. I think that's probably fine if you have a feel for preload, but I didn't. But trying to use a screwdriver and hammer and see a very subtle jump of a dial indicator on the other side is basically impossible. I eventually realized I was going to need an SST or at least SOMETHING to be able to slowly and smoothly turn the adjusters. For reference, if you want to pay $60 for the right tool, here are some numbers for you:
ARB bearing adjuster number P/n: 0770002
Toyota SST # - 09504-00011

I decided to rig something up. :D

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(Also, do you like my total lack of housing holder? I considered fabbing something up like in the videos linked at the beginning or as illustrated in the FSM, but then realized I could pretty much just balance the whole thing on the pinion flange. Only problem, it was constantly threatening to tip over and as mentioned before, that thing is HEAVY!! So caveat emptor).
Anyway, my ghetto SST worked great... the lag bolts were strong enough so they wouldn't bend as I put torqued the adjusters (nails in the board, SST v. 1.0, bent over when engaging the adjusters, FYI). And this was my breakthrough. The zero point was totally clear on the dial indicator, it's just a small jump of about .001" and it's only a tiny bit of resistance on the pinion side adjuster, but definitely obvious once you're not using a hammer and screw driver. Once you get to this point then per the FSM you just turn the pinion side adjuster 1-1.5 notches further and that's it... you have proper carrier bearing preload (CBPL)!! As a side note I noticed that the whole assembly is subtly but noticeably stiffer to turn. However, you should still be able to rock the whole thing back and forth to measure the backlash. When I had the adjuster in backwards the prescribed preload made the whole assembly REALLY stiff to rock back and forth, but that was much better when I fixed that mistake.

Sub Step D: Fine tune the backlash while maintaining CBPL.
Now we're actually pretty smooth sailing, believe it or not. You just turn one adjuster a little tighter and the other adjuster a little looser in equal measure, until you get the backlash to .006-.008. When doing this be sure to measure at 3 or 4 locations each time because backlash will not always be consistent around the whole ring gear. This was somewhat more acute for me because my ring gear is actually out of spec on runout.... I think it had like .006" or so when .003" is the max spec. That's why I wish I had measured that runout before I started bashing it off the old carrier and back on the new carrier.... If I'd known that it was already out of spec and hadn't had a problem I would have felt a lot more secure than wondering if I had now introduced a new problem. But at some point you've gotta just quit worrying too much and get the job done because you're wife is going to kill you if this seriously takes 5 days. (It took 4 - I know, embarrassing).

<Aside complete - back to backlash adjustment> Anyway, the FSM says to use the notches on the adjusters to measure how much you've tightened and loosened each side respectively, but the new ARB adjuster of course doesn't have the same number of notches as the stock adjuster, so I just used Sharpie marks on the adjuster rings and sighted the angle change from the bearing caps. This is probably overly OCD.

As you get close to having the backlash where you want it, be aware that you're going to need to reinstall a locking tab into each adjuster to keep them from wandering so aim to have a gap directly at 12 o'clock.
Sub Step C: Tighten the bearing caps and recheck the backlash (torque is 58 ft-lb). Again, if you don't have a giant vice or whatever to hold this whole thing while you torque, feel free to improvise.


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:)

Oh man... I forgot about drilling the hole in the housing... I did that before I installed the carrier..... (updated now)
 
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Step 10 - check the gear engagement pattern with some marking compound.
I'm just going to put this in here for completeness, but I skipped this step. I figured it was the same gears and same sized carrier and I was feeling a bit impatient and I didn't want to take the pinion bearings apart anyway, so I just didn't bother and took a leap of faith and reassembled without doing this. I don't know how crazy this was to skip this step, but I'm driving the car and there aren't horrible noises, so I seem to have dodged any potential bullets.

Step 11 - get the air seal housing assembled and installed.

In your ARB kit there is this little bearing looking ring with a copper tube brazed on the side of it - it's what ARB calls the 'seal housing'.

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You assemble 2 O-rings (~2" diameter) into the inner diameter with some oil for lube. In operation, what's happening is the new ARB carrier has that longer shoulder on the ring gear side that we tried to press the side bearing past. And with the ARB supplied adjuster ring that is lower profile, there is some space for this little 'seal housing' to fit right into that pocket of space onto the protruding end of that shaft. It pushes right up against the adjuster ring. There is a small hole on that shaft surface and the new o-rings inside the seal housing straddle that hole. From what I can tell that hole goes half way into the shaft, then makes a 90* turn and disappears into the ARB guts somewhere inside to make the locking magic happens. But the air seal is the way you get air pressure from your fixed tubing into a rotating differential. Cool! (would have been good if I DIDN'T scratch that surface up a little bit.... :doh:)

Side note - the o-rings in my kit were actually the wrong size; too small. I doubt this is common and I just called ARB up and they're sending me new ones. I was able to continue because I also have a front locker and that assembly specs the same o-rings and they were correct in that kit, but anyway the correct o-rings fit nice and passively into the seal housing. Anyway, just oil them up a bit and gently slide them into place. In the picture above they're already installed.

Once you've pushed that seal assembly into place there is a spring clip that hooks through the other odd cutouts on the air seal housing and clip to the bearing adjuster ring. It keep the seal housing from rotating with the diff. This is where I figured out that I had the adjuster ring on backwards, because that clip wasn't able to hook onto the adjuster ring properly. Then you just snap the ring over the outer diameter of the housing and away you go. Don't forget to install the locking tabs to keep your preload and backlash secure... I didn't even bother looking up the torque on that one, just torqued to 'Gutenteit'.. Anyway the manual is pretty clear here and this stuff is fairly straightforward now.

You'll notice that when you turn the ring gear that the seal housing will rock one way and then the other when you reverse direction. It seems odd that this thing moves around on it's shaft but apparently it's fairly self-centering.

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Here are some pics from the ARB manual.

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Step 12 - you're seriously in the final stretch now and the ARB manual is going to take you home, so here are just some general observations.

- Bending the copper tubing from the air seal housing - Just follow the excellent illustrations in the ARB manual. There is a note about using a brake line cutter if you need to shorten the tubing so as not to introduce metal fragments into the air system. I found the copper tubing to be just about the right length and since I don't have a brake tubing cutter and didn't want to buy one at this point, I just bent the tubing such that it used up all the length, right up to the 'bulkhead body' which is the piece you inserted into the tapped hole with LocTite red already. The O-ring is easy to lose, but I finally found it. Cinch the 'center compression nut' down and you are ready to reinstall the 3rd member back into the axle assembly.

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ScreenHunter_36 Aug. 25 12.25.jpg



Step 12.5 - test locker function. I just hooked up some shop air (90 psi) and listened for a satisfying clicking sound, which it made. Unforunately, my rubber tipped air nozzle leaks a fair amount of air so it was tough to discern if there was any leakage in the air locker parts. The ARB manual recommends testing for leaks, which I think is a great idea and I sort of did, but not as completely as they describe. There is a small ARB tester available that you can use to pressurize the line from the shop air, but has a ball valve and pressure gauge installed - basically a leakdown test. One could presumably rig this up as well if you could find the right fittings to match the line and already had a pressure gauge and some kind of valve. You pressurize the line and then cut off the pressure with the ball valve and watch the gauge to see if/how much the pressure gauge goes down and then start tracking down leaks if you have them. I just had my son activate it from far away into the end of the blue hose and I listened and painted a bit of soapy water around the areas that you might suspect a leak.... On not finding any, I just kept on trucking. If I'd had more hands one could also conceive of testing the locker and actually sticking an axle shaft in one side and seeing if the other axle slot on the opposite side turned. I just accepted as an article of faith that the new diff would work as advertised.

Step 13 - put 'er back in there!

My paper seal was pretty trashed, so I cleaned up both surfaces with a razor and some brake cleaner and used FIPG. That's Toyota's version of RTV ("form in place gasket" I believe... I doubt there's a giant difference). I had some from a prior job when I tried to reseal a leaky oil pan. Which was a fail. Anyway nothing's leaking yet from the diff.

The studs on the axle housing are long enough that I was able to hang the 3rd member pretty far out on the studs and then carefully apply the FIPG around the perimeter and then just slide the whole thing back into the silicone with a satisfying smush. Work quickly to torque bolts in a star pattern. 54 ft-lbs on those 10 nuts.

I also went ahead and hooked up the blue air line (which IS in the box, it's just under where the carrier had been) and left it coiled and zip tied up and out of the way so that no dirt or mud would get into the air lines and I even bent over and taped the last 2 inches of air line to keep the rest of the tubing semi-hermetically sealed. At this point I haven't actually hooked up the compressor or switches or anything... That part seems like a lot lower banana job to me than the the axle internals, plus everybody will probably do that a little differently.

Step 14 - axles back in (25 ft-lbs) and driveshaft back on (54 ft-lbs) and

Step 15 - say some prayers and take a test drive!


Thanks for reading, I had fun doing the project and writing it up. Hopefully it will be of help to somebody else. I know it will be a good reminder for me when I dive into the front one.

- Mark M.
 
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THIS IS HOW DIY's SHOULD BE WRITTEN!!! I have been contemplating an ARB locker install and this thread has provided me the information I need to feel confident I can handle it. I'm still going to wait until the thread is complete, but thank you for the time you have put into sharing this with everyone.
1) Clear, focused, well lit images
2) Detailed description of each step (including where you got stuck, mistakes you made, and areas for improvement)
3) Steps and sub-steps to keep things in order and manageable for anyone following along.
4) Light humor thrown in to make reading it enjoyable.

A+ work dude

If you're ever in Cincinnati... Beers are on me.

Thanks bass 1! What I was really hoping to do was just take some of the mystery out of this job, although sorry to still leave some surrounding pinion bearings.

Good luck, I think you can totally do it. (And not take 4 days like me...)
 
Step 12 - you're seriously in the final stretch now and the ARB manual is going to take you home, so here are just some general observations.

- Bending the copper tubing from the air seal housing - Just follow the excellent illustrations in the ARB manual. There is a note about using a brake line cutter if you need to shorten the tubing so as not to introduce metal fragments into the air system. I found the copper tubing to be just about the right length and since I don't have a brake tubing cutter and didn't want to buy one at this point, I just bent the tubing such that it used up all the length, right up to the 'bulkhead body' which is the piece you inserted into the tapped hole with LocTite red already. The O-ring is easy to lose, but I finally found it. Cinch the 'center compression nut' down and you are ready to reinstall the 3rd member back into the axle assembly.

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Step 12.5 - test locker function. I just hooked up some shop air (90 psi) and listened for a satisfying clicking sound, which it made. Unforunately, my rubber tipped air nozzle leaks a fair amount of air so it was tough to discern if there was any leakage in the air locker parts. The ARB manual recommends testing for leaks, which I think is a great idea and I sort of did, but not as completely as they describe. There is a small ARB tester available that you can use to pressurize the line from the shop air, but has a ball valve and pressure gauge installed - basically a leakdown test. One could presumably rig this up as well if you could find the right fittings to match the line and already had a pressure gauge and some kind of valve. You pressurize the line and then cut off the pressure with the ball valve and watch the gauge to see if/how much the pressure gauge goes down and then start tracking down leaks if you have them. I just had my son activate it from far away into the end of the blue hose and I listened and painted a bit of soapy water around the areas that you might suspect a leak.... On not finding any, I just kept on trucking. If I'd had more hands one could also conceive of testing the locker and actually sticking an axle shaft in one side and seeing if the other axle slot on the opposite side turned. I just accepted as an article of faith that the new diff would work as advertised.

Step 13 - put 'er back in there!

My paper seal was pretty trashed, so I cleaned up both surfaces with a razor and some brake cleaner and used FIPG. That's Toyota's version of RTV ("form in place gasket" I believe... I doubt there's a giant difference). I had some from a prior job when I tried to reseal a leaky oil pan. Which was a fail. Anyway nothing's leaking yet from the diff.

The studs on the axle housing are long enough that I was able to hang the 3rd member pretty far out on the studs and then carefully apply the FIPG around the perimeter and then just slide the whole thing back into the silicone with a satisfying smush. Work quickly to torque bolts in a star pattern. 54 ft-lbs on those 10 nuts.

I also went ahead and hooked up the blue air line (which IS in the box, it's just under where the carrier had been) and left it coiled and zip tied up and out of the way so that no dirt or mud would get into the air lines and I even bent over and taped the last 2 inches of air line to keep the rest of the tubing semi-hermetically sealed. At this point I haven't actually hooked up the compressor or switches or anything... That part seems like a lot lower banana job to me than the the axle internals, plus everybody will probably do that a little differently.

Step 14 - axles back in (25 ft-lbs) and driveshaft back on (54 ft-lbs) and

Step 15 - say some prayers and take a test drive!


Thanks for reading, I had fun doing the project and writing it up. Hopefully it will be of help to somebody else. I know it will be a good reminder for me when I dive into the front one.

- Mark M.


Question: the bulkhead kit comes with the locker or this is a group of items that you must buy separated ?
 
Thank you for this post. I feel alot more comfortable tackling this job now. Hows it holding up?

Sorry I didn’t check this very quickly. I’ve actually sold this car now at this point. It did hold up fine though. I ran the Rubicon on it a few months after this write up and the front and rear lockers were CRITICAL. I also integrated the lockers into the dash by purchasing the stock locker dial and adding the correct bulbs into the dash cluster so everything lit up correctly when you turn the dial. That was a little more complicated and I had to learn how to solder but in the end wasn’t very hard. I just had to figure out how relays work and purchase a few and find the wiring diagram for the stock locker ECU so I could intercept the right wires to go in and out to the relays. There are excellent writers ups in MUD for this already. Good luck!!
 
Question: the bulkhead kit comes with the locker or this is a group of items that you must buy separated ?

Sorry for the very late reply, haven’t been on mud in about a year as I sold my 80 (boo, I know). Anyway, I believe the wiring harness and switches came with the compressor but I’m not positive at this point. I’m pretty sure the actual differential carriers/lockers themselves were just on their own.
 

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