FJ40 rear axle swap: recommendations? (1 Viewer)

[1thirdcent]

I'm thinking of swapping my FJ40 transfer case for a NP205 that I've had laying around. That means I need a centered differential for my '73 FJ40.

Does anyone out there have a recommendation for what axle might be best?

I'm currently running 1.25" spacers on the rear. I haven't pulled the wheels to measure the backing plate to backing plate width but found on line that it should measure 55" without spacers, so the axle width with spacers should be 57.5". I'm thinking anywhere from 55" to 58" backing plate to backing plate would work.

Has anyone out there done an axle swap and if so, what worked for you?

 

[Chris Wilcox]

If you are up for a project a FZJ80 rear axle would be perfect. Use two short side shafts and it will be centered, full float, elocked if you buy one of that style, and more rugged. Disadvantage is that the rotors will not fit 15" wheels. If you are even more ambitious you can buy FJ cruiser rotors and rework the backing plates, then 15"s fit. I went this route but maintained the off center by going custom short side shaft.

http://cruiseroutfitters.com/tech_rear_axle.html

For axle lengths. Stock us 1600mm (63") WMS, from memory.
If you use two short side shafts you lose 7.375 ending up with a 55-5/8" WMS (1412mm) which is close to the 1400mm stock.

If you do go this route then when you shorten the housing on the long side, build yourself a jig using rollerblade bearings so you can spin the housing prior to welding. This way you can check the runout of the full float spindles before cutting and prior, during and after welding to ensure you have a straight axle. Ask any millwright or machinist if necessary on how to check runout using a dial indicator.

One option anyway.

 

[TCinVA]

You could use a mini truck rear axle if you're spring over. Another option would be a 6 lug 14 bolt out of a "light duty" 2500 Chevy 4 wheel drive truck from the late 80's/early 90's but it may be too wide.

 

[Fast Eddy]

If you do go this route then when you shorten the housing on the long side, build yourself a jig using rollerblade bearings so you can spin the housing prior to welding. This way you can check the runout of the full float spindles before cutting and prior, during and after welding to ensure you have a straight axle. Ask any millwright or machinist if necessary on how to check runout using a dial indicator.

When I did mine we just bolted the axle to the assembled hub, inserted the axle, centered it by feel and tacked it in place. I don't think it's critical much beyond 1/8" or so. We also sleeved the tube. I should pull the axle shaft sometime and see if there is any wear at the splines.

 

[shelfboy1]

dont know what strenght you need but a rear axle from a 92 or so trooper or acura is 6 lug disc brake with drum ebrake close to same ratio some have limit slip and they are dana 44,s .if your using this truck off road then the angle should not matter since so many vehicles came with and still come with offset axles

 

[Clutchee]

Cool setup I saw was from Woody-

Cruiser axle, cut long side down, the put mini truck outers & axles.

Centered rear w common axle for use on either side.

 

[Howard705]

How about early ford bronco 9"- Width about right. 5 on 5.5. Can it be redrilled to 6 on 5.5? Strong

 

[bikersmurf]

What about an FJ rear axle? Toyota Tundra? Tacoma?

 

[69LC]

I'm building a 14B FF to run 6 on 5.5. It was from a dually C&C van. I had to shorten the tubes 7.5", shaved the bottom and ring gear. I will use common domestic discs for brakes. I will never have to worry about strength. If my shortened stock axle shafts fail, I can pony up to aftermarket custom shafts. I will be running a Ford 205. Why all the mess? It's fun.

 

[Toyoland66]

I am assuming the rest of your drivetrain makes running a 205 make sense?

If you want a 58" wms rear your easiest option is a hybrid rear axle. It combines a LC housing with a mini truck housing/ shafts. Woody has a good write up. A IFS or Tacoma rear will get you the width you want. What are you going to run in the front to match?

 

[Tigerstripe40]

F/2F or mild V8 (283, 4.7 toyota, 4.8 GM), I'd say go with a Taco 8.4" rear end with Cromo shafts.

Anything bigger like a 5.3+ V8, 14 bolt, HP Dana 60, or Ford 9"

 

[woytovich]

Slight hijack, maybe....

I too am thinking about a centered rear diff option for a 40 (actually a 45LV). I would REALLY like to avoid custom fabrication and/or the need for custom shafts. Does anyone know the width of stock rear axles for the Tacos and Tundras... and Mini/4Runners too I guess (especially the later v8 Runners).

 

[pb4ugo]

A dana 44 is a step backwards.

My mini/LC hybrid rear

 

[Fast Eddy]

I too am thinking about a centered rear diff option for a 40 (actually a 45LV). I would REALLY like to avoid custom fabrication and/or the need for custom shafts.

Reread reply #1. The "custom fabrication" is a cut/sleeve/weld. We did it on a welding table in a couple hours. It's not as hard as a cut and turn.

The result is all-Toyota including the axle shafts, disc brakes and parking brakes if you need them; e-locker too, if you want.

My only warning is to use a plasma cutter as the first step to cutting off all the 80-series brackets. There are a lot of them. It took me the better part of a day to strip the housing with a grinder.