Topic: 2wd Third Member Help

[Eighty8Cruiser]

I have been getting conflicting answers everywhere I call, so I appreciate ANY information that I can get.

A little bit of back story.  The stock diff was going out, so I went to the junkyard and got a third member out of an 84 2wd (axle code G662).  I put that diff in and was doing fine until I decided that the 3.07 gearing sucked for bottom end, so I decided to change the gearing.  I happen to have a 3.91 ring and pinion from an 88 supra and figured I would use that.

Now, here's my problem.  I have everyone telling me that I have a 7.5" rear end because there are no 2wd trucks with an 8" rear end.  I'm not calling anyone a liar, or saying they don't know what they are talking about, but I do know what I'm looking at.  The carrier bearings on the 75 are the same size as the 84.  The axles fit in the 84 carrier and the supra lsd carrier.  The ring gears are the same size from the 75 (4.375), the 84 (3.07), and the 88 supra (3.91).  The only difference is the pinion head from the 88 supra, it's a little taller than the 75 and 84 pinion heads.  I read on the internet that you can use the inner pinion bearing for an 86 and newer 4 cylinder differential because the 86 and newer pinion heads were taller than the 85 and older pinion heads.

So, finally, here's my question.  Can I get a differential rebuild kit for an 86 and newer 4cyl diff and use it in my 84 housing since I will be using the gears from the 88 supra?

This is the badge from my truck.



These are the two housings I have right now.  The one on the right is from the 84 and the one on the left is the stock 75 housing.



I was also told that all supras had 7.5" rear ends, but this one that I pulled out myself, was just as big as the other two truck ring gears and fits on the 84 carrier.



I'm not out to prove anyone wrong, I just want to get the right parts that will work for me.  Thank you ahead of time for your help.

[jrock]

I think you've just proven your own point   8" 4cyl it is. Im not 100% about the Supra but you've got it all there and its looking good for your side.

[lone walker]

5 lug rear end?

[tgmaul88]

so are 2wd trucks 7.5 or 8"

[Eighty8Cruiser [OP]]

It's a 5 lug rear.  And as far as I know, 2wd trucks came with either 7.5" or 8" rears, but 7.5" was more common.

[OOPS]

so are 2wd trucks 7.5 or 8"

Yes! some were 7.5 some were 8!!

[Sparkplug]

1 ton 2wds, had the bigger rear end. Some think the 4 speed equipped trucks did also, but thats not the case.

I believe some 3/4 ton have it also, but im not positive. Its a funky ass looking dif. 8 inch 5 lug

[jimbo74]

While the 1 ton rears were 8" , I owned a standard half ton with an 8". It was 5 lug. I swapped it with a 4.56 rear from an 86 4x4 4runner

[Rocksurfer]

Some trucks came with an 8", as did some Supras.

[jrock]

What's a 7.5 rear end look like?

[Rocksurfer]

What's a 7.5 rear end look like?

I looked for just a pic but found a video....

[Nimyad]

8-inch rear ends came in pre 78 2wd trucks and are completely compatible with other 8-inch axles. Supra LSD are 8-inch

[GreyMax]

I know I am super late to this thread but if anyone needs a correct answer to this question from someone that has done countless weeks in 2wd Hilux research, I have one. If in fact you do have a 8” 5 lug differential axle code G662 it came out of a 2wd 4 speed or a 1 ton truck that was manufactured prior to the 89 year. Toyota did make a 2wd 8” After 89 but they only came in the dually and Dolphin RV. Toyota did also put the 5 lug 8” in the early turbo Supra as well. The pre 89’ 8” 5 lug will not be a perfect fit into a 89+ Truck because they are more narrow by about an inch and the spring pads are more narrow buy 1/2 than the 89+ 7.5 2wd differential. The 8” that came with the 3:07 ring gear was equipped Only in the 4 speed models. This was done because of the lack of a 5th gear. The reason the 4 speed came with an 8” was that it was marketed as a industrial work truck that would rarely see the highway. The carrier in the 4 speed truck is not compatible with any other gear ratio because it has a offset pinion gear “because it is so large”. The 1 ton 8” that came in the non dually 1 ton trucks came equipped with a standard 3:73 gear but could be ordered with a 4:10 as an option. All  8” 2wd differentials also had 31 spline axles for strength. One thing to note about these carriers is that they are much shorter than the 4x4 carriers. If you deside that you want to go to a larger gear from the 3:07 in the 4 speed and cannot and most likely will not find a 1 ton or a turbo supra carrier in a wrecking yard, and have no choice but to use a 4x4 carrier, you will need to shorten your driveshaft or you will stab your transmission under full cycle. I hope that this helps anyone that needs it in the future that needs information about the G662 coded axle.