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.
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!!)
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.
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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