the_supernerd

I want to regear my 4x2 that has an 8 inch rear end. I was reading that some 3rd gen 4Runners and Tacomas come with the same 8 inch third. If I understand correctly, all 4Runners up to '02 came with the 8 inch, and only TRD Tacomas came with an 8 inch. Does this mean I can get a third from an '02 4Runner and bolt it in my '88 4x2? Are all 8 inch thirds the same regardless of 4x4, 4x2, or year?

the_supernerd

From what I have found, most 5 lug 4x2s came with the 7.5 inch, but some came with the 8 inch. Mine has the 8 inch with 3.07s As far as I know, the 4x2 8 inch came with 3.07 (4 speed), 3.42 (turbo & V6), 3.90 (1 ton) and 4.11 (some cab & chassis).

I know that mine is 8 inch, but I am wondering if it swaps with a 4x4 8 inch, mainly from the 3rd gen 4Runners so I can get a newer one with less miles.

PismoJoe

Great site with identification info

http://www.off-road.com/trucks-4x4/t...ion-18588.html

PismoJoe

This site has good comparisons for thirds, what swaps and what doesn't http://home.4x4wire.com/erik/diffs/

DeathCougar

iTrader: (23)

Wrong

Toyota made a 2WD 5 lug one ton with an 8" diff.

Most common ratio was 3.42, but I have seen others as well.

They also built the Turbo 2WD trucks with 8" diffs, and they were 5 lug as well.

the_supernerd

That second link is the one where I initially got my information. It says the 3rd gen 4Runners use the same 8 inch differential with a "new and improved" housing. I am wondering if the entire third, including the housing will bolt up, or if it is just the gears that can swap.

My axle is a G662, so 8 inch, 3.07, 2 pinion without limited slip. It has a carbureted 22R and a W46 transmission. Usually carbureted trucks have a G transmission and 4x2s have a 7.5 inch diff. I have found a few other trucks on here with my same combination, and they usually cause some confusion.

The earlier dually trucks and Toyota based RVs had 8 inch differentials with dually adapter rims. These were a problem on RVs because the weight of the RV combined with the leverage of the outer dually wheel were snapping axle shafts. There was a actually a safety recall for RVs to replace the axles with full floaters. You can read about it here:

http://www.toyotamotorhome.org/class...s/Axle_FAQ.pdf

DeathCougar

iTrader: (23)

G662....do you have a motorhome?!

the_supernerd

The truck with the axle code G662 is not a motorhome. It is a base model 4 speed pickup with 3.07 gears for economy. I brought up the motorhome because razed was talking about the dually adapters. I just parted out a motorhome that had a full floater with 4.30s on it and that is where I got some of the motorhome information.

DeathCougar

iTrader: (23)

I was asking because its weird that a base model truck has an 8" diff.

I would verify that is what you have before ordering a diff from somewhere.

Something else to consider is axle spline count. I am not 100% sure 2WD and 4WD use the same size and count splines

the_supernerd

I always thought it was strange that 3.07s are 8 inch. I checked the axle code, the third look just like the 8 inch in my 4x4 and different than the 7.5 I have in my yard, so I am 99% sure it is 8 inch. I have also seen a few other trucks with the same axle code.

I will definitely research the spline count before I buy a new third.

Magnusian

My pickup is G662 as well. The 3.071 gears are slapped onto the 4spd G40 tranny setups from what I can tell, so that 4th gear can maintain highway speeds at a reasonable rpm with stock tyres. Accelerates like an old woman with a cane.

Spline count is the same as the 4wd axle shafts (lockright for 2 pinion 3rds fits my shafts), the only difference from the 2wd 8" rears seems to be the drive flanges on the axle shafts for 5-lug and brakes. Well, that and the topmost fin on the 2wd 8" 3rd sticks out more.

iamsuperbleeder

how do people acquire such knowledge

DeathCougar

iTrader: (23)

Interesting, wonder why that may have been?