V8 4WD 8.2 Swap

[TheHennDoggg]

Hey everybody,

I recently was lucky enough to come across an 8.2 axle housing and diff with an Elocker for $212. I got it at an LKQ from a 2010+ FJ Cruiser. I picked it up with the help of my friends and I'm going to swap it into my 4runner.

Is there anything that I need to know before beginning this swap? I don't think there is many modifications needed to fit it. I'm getting a new lug stud, brakes (rotors, calipers and lines), breather and wiring harness so far!

 

[rdruss]

Hey everybody,

I recently was lucky enough to come across an 8.2 axle housing and diff with an Elocker for $212. I got it at an LKQ from a 2010+ FJ Cruiser. I picked it up with the help of my friends and I'm going to swap it into my 4runner.

Is there anything that I need to know before beginning this swap? I don't think there is many modifications needed to fit it. I'm getting a new lug stud, brakes (rotors, calipers and lines), breather and wiring harness so far!

Famous last words! Seriously, I hope you are correct and it does go smoothly!

 

[Direwolf82]

I would double check to make sure your gearing in the new diff matches your front gear ratio. If it doesn't it's going to be a little tougher on the drivetrain than needed.
And if it were me I would measure the living crap out of the suspension mounts, spring perches, driveshaft connection and all that fun stuff before I pulled it apart just to know if I'm looking at an hour or two of stuffing in a new diff and then however long to hook it all up versus having to cut all the existing mounts off the diff and welding in the mounts from the old diff or whatever might need to happen. It takes me a couple hours of plasma cutting and grinding to prep a diff for a full custom install.
Good luck! I like the sound of the project, wish you the best with it.

 

[That_Titanium_4RNR]

I would double check to make sure your gearing in the new diff matches your front gear ratio. If it doesn't it's going to be a little tougher on the drivetrain than needed.
And if it were me I would measure the living crap out of the suspension mounts, spring perches, driveshaft connection and all that fun stuff before I pulled it apart just to know if I'm looking at an hour or two of stuffing in a new diff and then however long to hook it all up versus having to cut all the existing mounts off the diff and welding in the mounts from the old diff or whatever might need to happen. It takes me a couple hours of plasma cutting and grinding to prep a diff for a full custom install.
Good luck! I like the sound of the project, wish you the best with it.

I believe 5th gens were only offered in 3.73. And almost alllll 4th gens are 3.73 but I have heard of some that are 3.91

 

[doofenshmirtz]

Hey everybody,

I recently was lucky enough to come across an 8.2 axle housing and diff with an Elocker for $212. I got it at an LKQ from a 2010+ FJ Cruiser. I picked it up with the help of my friends and I'm going to swap it into my 4runner.

Is there anything that I need to know before beginning this swap? I don't think there is many modifications needed to fit it. I'm getting a new lug stud, brakes (rotors, calipers and lines), breather and wiring harness so far!

Is your existing 8in axle housing in good shape? I may be willing to buy it off of you. I messed up my rear diff drain bolt, and I don't really like the fix I did for it. A new housing would be a wonderful solution at the right price. I know you'll need plenty of time to actually do the swap before it'd be off the car.

 

[Inv4drZm]

Mechanically they are all the same. Shock mounts, link mounts, spring perches, driveshaft. Just have to get the elocker wired up. Manual FJ's will have 3.91 gears while the autos have 3.73. Check out NYCRunner's build thread he has pictures of his swap.

 

[hinmo24t]

I believe 5th gens were only offered in 3.73. And almost alllll 4th gens are 3.73 but I have heard of some that are 3.91

i have the 3.91 in 04 4speed v6 i believe. love it

 

[That_Titanium_4RNR]

Mechanically they are all the same. Shock mounts, link mounts, spring perches, driveshaft. Just have to get the elocker wired up. Manual FJ's will have 3.91 gears while the autos have 3.73. Check out NYCRunner's build thread he has pictures of his swap.

The one he got is also from a 2wd FJ. How odd is that...a 2012 FJ 2wd with a diff lock...I know the driveshaft from the 4th gens was different between 2wd and 4wd. Do you know if the pinion flange is different on the 4wd vs 2wd 2010+ FJs?

 

[Inv4drZm]

The one he got is also from a 2wd FJ. How odd is that...a 2012 FJ 2wd with a diff lock...I know the driveshaft from the 4th gens was different between 2wd and 4wd. Do you know if the pinion flange is different on the 4wd vs 2wd 2010+ FJs?

I installed a 2wd differential/ 3rd member onto my 4wd driveshaft (by accident ordered the wrong part).

The differential will have a thick harmonic balancer where the driveshaft flange bolts to vs the thin flange the 4wd differentials have. The 4WD setup uses nuts on the backside whereas the 2WD setup the harmonic balancer itself is threaded so you can thread the bolts straight into the balancer.

The mounting flange length is the same overall you won't have to worry about driveshaft lengths or anything. The reason why the driveshaft is different between 2wd vs 4wd is that it is longer (no t-case). The mounting flange is the same from what I can tell.

Here is what mine looked like with the 2wd flange. I'm assuming the FJ's are the same as ours.

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[That_Titanium_4RNR]

I installed a 2wd differential/ 3rd member onto my 4wd driveshaft (by accident ordered the wrong part).

The differential will have a thick harmonic balancer where the driveshaft flange bolts to vs the thin flange the 4wd differentials have. The 4WD setup uses nuts on the backside whereas the 2WD setup the harmonic balancer itself is threaded so you can thread the bolts straight into the balancer.

The mounting flange length is the same overall you won't have to worry about driveshaft lengths or anything. The reason why the driveshaft is different between 2wd vs 4wd is that it is longer (no t-case). The mounting flange is the same from what I can tell.

Here is what mine looked like with the 2wd flange. I'm assuming the FJ's are the same as ours.

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All good info! the axle actually had a flange that looks similar to the 4wd 4th gens and not that dampener from the 2wd, so I guess in 2010 when they went to the 8.2 they didnt use different flanges

 

[TheHennDoggg]

Mechanically they are all the same. Shock mounts, link mounts, spring perches, driveshaft. Just have to get the elocker wired up. Manual FJ's will have 3.91 gears while the autos have 3.73. Check out NYCRunner's build thread he has pictures of his swap.

Thanks man that is some killer info!

I'm going over to his build thread now. The FJ me and Titanium took it off of was really really weird, but it was an auto and I believe that is what determines the gear ratio. I think I'm going to go and make a wiring harness for the locker with a "safety" so I cant actuate it at speed as well.

Here's some pics of the axle:

 

[TheHennDoggg]

Is your existing 8in axle housing in good shape? I may be willing to buy it off of you. I messed up my rear diff drain bolt, and I don't really like the fix I did for it. A new housing would be a wonderful solution at the right price. I know you'll need plenty of time to actually do the swap before it'd be off the car.

Yeah it will take me a good bit, but it is in OK shape. I'll get pics sometime down the road but the housing has 200k on it as of this week. Are you in East NC? It'd be a bear to ship is my only problem.

 

[doofenshmirtz]

Yeah it will take me a good bit, but it is in OK shape. I'll get pics sometime down the road but the housing has 200k on it as of this week. Are you in East NC? It'd be a bear to ship is my only problem.

I’ve got family up that way, so I know what I’m in for with the drive. I’d come get it or meet you somewhere agreeable - I’m in no rush. I JUST changed my diff oil, so I’d likely not do anything with it for quite a while.

 

[TheHennDoggg]

About to pull the trigger on a brake system. Attached is what i have been thinking.

Is this in- line with what y'all would do or is there some other option I'm missing? Also, is there anywhere I can get the hard lines that are on the axle or do I have to cut/ bend them myself? I've never done it before

 

[TheHennDoggg]

Been itching to work on this thing but its been raining and no parts are in yet, so I took out the bent lug stud and rotors to get a look at the parking brake situation. The parking brakes have plenty of life left is what it seems so I'll probably just clean them up.

I also decided not to buy calipers and use the ones that are either on my 4runner or get some from the few 1st gen Sequioas they have in the junkyard, hoping that the 8 inch axle calipers are compatible. It's gonna be damn close if they aren't lol. Same thing with the axle hard lines as they look like they will be close if not the same to fit.

Going to do research on how to make the E-locker wiring harness myself since almost $200 for a premade one is pretty bonkers!

 

[TheHennDoggg]

Got some Centric brake lines for the ones that were cut by the people who got it before me at the junkyard

 

[Jembrmstr]

I’m about 75% done with making an elocker work on my runner, I have a few sites that have really good instructions on how to do so, if you’re Interested send me a PM and I can text you links to the sites or someone can teach me how to hyperlink on the pages here from my phone.

 

[TheHennDoggg]

It may not be a surprise to some of you, but here is confirmation that 8 inch and 8.2 inch axles can receive the same parts:

Went to the junkyard yesterday and picked up some hard brake lines, calipers and caliper brackets from a 2003 v6 4runner. These fit on the 2012 FJ axle perfectly, I even used the bolts and brackets from the junkyard on the new axle. Even less of a surprise is that the Metaltech LT brake lines (for my 2003 4runner) also fit. I have 1990 (or second gen) 4runner rear sway bar end links coming in soon and that will be about everything to have the axle in 100%.

I have not began making the locker harness yet as my attention for this first part is to have a drivable vehicle, especially since we cant wheel till mid May at the earliest due to the coronavirus in North Carolina . Will be getting the parts soonish, once I know the axle is in and working.

 

[JONBOY345]

I’m about 75% done with making an elocker work on my runner, I have a few sites that have really good instructions on how to do so, if you’re Interested send me a PM and I can text you links to the sites or someone can teach me how to hyperlink on the pages here from my phone.

Just copy and paste the links in a reply and they should auto-format for you.

 

[duffdog]

I’m about 75% done with making an elocker work on my runner, I have a few sites that have really good instructions on how to do so, if you’re Interested send me a PM and I can text you links to the sites or someone can teach me how to hyperlink on the pages here from my phone.

Its super easy to make the elocker work manually. All you need to do is connect a momentary on-off-on switch to the motor using 2 relays in reversing polarity (like a window motor). The engage/disengage harness to the right of the motor connects to the light on the switch to tell you when it is fully engaged. Thats it.

There are other ways to do it that include using 4 relays, but those methods are both overcomplicated and provide less current to the motor making it take longer to engage.