120 Rear Diff- Swap

[EL_3grab]

Since the 120 LC have a centered rear diff- ... is there any major issue not to swap it in a 100 LC (beside the 32 to 30 splin shaft and 6 lug pattren) ..

just the thought of it is a huge relief for me ..

Benefit from the swap:

1- aftermarket TC (Atlas 4 her i come )

2- Bolt-on rear R&P

Discuss ..

 

[EL_3grab]

yeah .. this is only apply if you want to change the TC or every thing in my case ..

 

[Letsgomoreplaces]

120 diff

The 120 rear diff is much smaller than the 100 rear diff and would not be ideal in cruiser.

 

[Jim_Chow]

120 diff is the same on the 4runner and FJ cruiser. A number of FJ Cruiser owners w/ locked diffs have had them blow apart while wheeling, and that vehicle weighs a LOT less than the 100. The 120 diff is only 8", 100 diff is like 9.5"...big difference. If you installed the 8" diff in the rear of a 100, I'd be surprised if it didn't blow up. If you like the 8" because it's centered, the old 4runners (85-95) all use the centered 8" diff, and there are way more mod options availale than w/ the 120.

 

[EL_3grab]

100 Gross vehicle mass = 3180 kg

120 Gross vehicle mass = 2900 kg

..

in my project i aim for under 2500 kg (Alu. engine and TH400 trans, no intiror, plastic windows, and polyethylene fuel tank) ..

and no crawiling here .. just sand and sand ..

this is my only way out ..

 

[100 TD]

If you need to move the differential placement, CUT and SHUT the 100 housing and axle that you have, this will give you something much better than a 120 diff and housing, IMHO! My .02! (The cutting and welding can actually be stronger than original AFAIK)

 

[EL_3grab]

yes .. but still no support from the aftermarket parts .. and i can't even do a 4.88 without spending more than 1000$ .. add to that .. this solution seems more $$$ ..

120 rear axle .. have that support .. due to the FJ and 4runner in USA = more parts available .. no hope for the 100

ARB Diff- and 4.88 .. will handle very well .. i think

and i know a mathcing wheels for both the front and the rear pattren ..

 

[Letsgomoreplaces]

You can change the gears in 100

It is still cheaper to buy the extra parts you need to keep your existing diff ( that will hold up) . Then to go to a sub-par diff that is not going to hold up well. If you want to change out to a centered diff, why not use something common and larger like a Dana 60?

 

[Letsgomoreplaces]

arb rear diff

Also if you are going to do a rear arb anyway, there is not much cost difference. W/ the lower gears you may not even want to change out the t-case

 

[EL_3grab]

why 120 .. because already i have RD23 laying around ..

4.88 for the 35inch tires to keep rpm near stock (when 4wd not engaged) .. and it will cost me 300$ Max. both R+F

Atlas 4 or Atlas II .. to not worry about my TC when going high speed .. and the choice of several low gears ratio ..

and it will be in this order .. Gen3>TH400>Atlas ..

i don't know .. but it seems to be the 120 swap is my solution to all my problems .. with the least amount of money spending ..

 

[ridgerunner]

The 100 axle isn't that offset, why worry about it? There are people running 80 axles with centered outputs...

 

[EL_3grab]

I'm confused now ..

all the posts say i can't (or not advisable) to run a center output shaft to offset axle .. and there is a so many thread talking about this ..

but really .. don't think the idea is that bad .. yes its weaker .. but it will not blew the moment i step on the gas ..

just keep every things considered .. Weight, ARB Diff-, some quality R&P ..

1600 Kg is the Max. weight on the 120 rear axle ..