I got a 91 2wd 4 cylinder 5speed and im looking for other rear end options. Right now I got a 7.5 with 3.23 unfortunately. Looking to move to a 3.90 or so. Would I need to find an 8 inch? Is there a posi available for the 7.5 or will it last if I weld the spiders?

 

I would only weld the spiders (Lincoln-Locker) if the truck is a dedicated drag truck or Off-road. Even then I wouldn't recommend it. The loss in handling isn't worth it in my opinion.
As for rear end options, they are plenty for our trucks as there is quite an aftermarket going for them as well as plenty of info available on Toyota diffs both here and on just about any 4x4 site.
Other options range from swapping in a Toy 8-inch, a Ford 8.8 from an Explorer or even ordering a custom Ford 9-inch. Some guys on here even have swapped out the independant rear suspension from a celica (someone chime in and correct me if I got the car wrong) And after looking at one I don't see why a Corvette independant rear couldn't be adapted to work. It all depends on what you want and how much you want to spend.

 

G code 8" is the only one worth swapping in my opinion. Mega aftermarket, gearing choices from 3.43 to 4.88 from the factory, limited slips and even a selectable locker are factory options. Drop a V6 3rd member in it and it will hold more power than 99% of people will put to it. Plus it's a bolt in, the correct width, the brake lines and e brake are also a plug and play.

 

7.5 rear locker

Amazon.com: Spartan Locker for Toyota 7.5" with 27 spline axles, includes heavy-duty cross pin shaft.: Automotive

 

ive been welding all my diffs. it sucks in the rain... but then again, how often does it rain here in LV. i got a 430, 456, and a 373 all welded. this and a line lock. makes camaro guys turn and grin when smoking up the rears at a stop light

 

You mention it's a straight bolt in.
What about the driveline and U joints?

Will I still be able to use my driveline and U joints?
Here's what I'm thinking of swapping because my rear isn't sounding so nice,

My truck is a 1991, 1/2 Ton, 2wd, 22RE, W55 Manual Trans
The door jam is marked Model RN80L-TRMREA
Rear Code F372= 7 & 1/2" Ring Gear, 3.58 Gear Ratio, 2 Pinion, Open Diff




In a salvage yard I found a 1989, 1/2 Ton, Extended Cab Truck, 2wd, V6, R150 Manual Trans.
The door jam is marked Model- VZN90L-CRMDEA
Rear Code G382= 8" Ring Gear, 3.42 Gear Ratio, 2 Pinion, Open Diff

At the salvage yard

 

Measure your spring perch width and compare it to the donor truck. If they are the same width it's a direct 100% bolt in. The 8" diff is about an inch longer than the 7.5" but I've never ran into driveline issues since there is more than enough compression travel available.

If the perches are wider than your current rear end simply pull the u bolts and plates to use in your truck.

 

Hmm, how much compression does one need to allow for? I sure as hell don't want to bottom it out and screw my trans.

And of course someone already made off with the U bolts and brackets. I'm guessing that the only reason the rear is still there is because of the 3.42 ratio. I don't use my truck for a stoplight bruiser or a 4x4 so that doesn't matter to me much. I can't imagine the .16 difference in ratios being much slower revving.

 

Your driveline will be fine.

As for the u bolts, if your truck has perches wider than the springs you're home free either way. If you have spring width perches then you're going to have to find a set of u bolt plates from a 2 wheel drive truck that uses them.

 

So I did some measuring on my stock 7 1/2" rear. Pretty much posting it so I don't loose the results and have something to reference if I need it.

1991 22re 1/2 Ton Short Bed 2WD
Leaf Spring width
2-3/8"

Outside Spring width measured from just behind front eye hole to the one on the other side
42"

Center of mounting pad to center of mounting pad
39 1/2"

Brake Backing Plate to Backing Plate (inside)
51 1/6"

Length of third member extending from housing
8 11/16"

Differential flange/Driveshaft Yoke bolts
10 x 1.00

 

I have stock 8" u-bolts if needed. I'm in the middle of getting my 8" all cleaned up and powder coated before install.

 

I might have to take you up on that, parts around here are a little scarce.

 

The u bolts are the same it's the plates that are different if anything.

 

Grrr, no wonder they're gone.

Anybody have those?


Gunna go look at it a little more in a bit. Taking measurements and comparing where the driveline bolts up to see about the bolt hole pattern and size.

 

Well I checked it out earlier toady. The measurements are the same except for the third member being longer. I think it's only about 3/8 inch longer but the way it was positioned I couldn't measure it accurately. I also noticed the drainage hole is on the other side. My driveline bolted right up, same diameter bolts and stagger. I took a chance and purchased it.

What was actually missing on the donor rear is the top plates and the U bolts. The lower plates were still bolted to the shocks and both looked better than mine so I got them both. I'm thinking I won't need the top plate or the U bolts because the center of the spring locating hole in the mounting pads was the same. I'm talking about the pads welded to the housing.

There was only two leaf springs on the donor truck and mine has three but both are 1/2 tons
I didn't see any signs of a lowering block either.


I checked the play on the pinion (backlash) and it was minimum. The one in my truck seems very excessive. I removed the top breather and turned the thing upside down. The gear oil that came out looked really clean with no sign of water. The backing plates are pretty flattened from rough handling with the drums off. I'll have to straighten them out with a small pair of pliers or whatnot for now.

I would try to swap mine but both sides suffered from leaking wheel cylinders and were rusty. I tried to paint them with VHT Caliper paint to get some chemical resistance but that didn't work so well. The paint went on nice in 80 degree heat and I let it sit for a week in 80 degree weather before I handled it. It stuck good but with a little brake cleaner it starts coming off. Maybe it does a lot better when you bake it in the oven for a while. It didn't say that's what needs to be done on the can but when you go to the website you'll see it.

It might take me a couple of weeks to do the swap because I want to get the thing cleaned up real good and I need some help lifting and such. I'm also having new U Joints installed. I'd do that myself but these look pretty rusted and I'd rather let a shop that specializes in that type of thing with the correct tools give it a go. I'm gunna clean them up with a wire brush and hit them with PB Blaster and let it sit before I take them in.

 

What leaves were left on the other truck? Main and overload or main and second? It's very common to pull the second to drop the rear a couple inches without blocks

If your u joints are still solid and mover frely leave them. Stock joints are far superior to any aftermarket stuff.

 

The overload spring was missing from the donor.

My stock U joints show signs of leakage and this truck wasn't treated well before I purchased it. I purchased OEM Toyota to replace them.
Hopefully the shop won't be upset with me. For the most part they use Spicer.

 

So I'm having a bit of trouble with my swap. Almost all of the 7 1/2" is unbolted and I got the 8" cleaned up and waiting.

Turns out the mounting pad that's welded to the rear on the 8" is a lot narrower than the mounting pad that's on the 7 1/2". The rubber isolation pad on the 7 1/2 rear won't fit in the 8" lower spring clamp plates so I'll have to locate some. (This made me really start comparing parts)

It's got me thinking that I really need to locate the top portion of the 8" leaf spring clamps specific to the V6 8" 1/2 ton before I can install the rear.
All I was able to get was the lower portion of the clamps that the shock bolts to.
I'll need the Rubber isolation pads too but that shouldn't be that big of a deal to get from a store.

I believe White trash mentioned that I need all of the V6 8" 1/2 ton hardware earlier but I got what I could. If I can't find them soon I'm screwed because this is my daily driver and the weather is going to turn to cold and ugly on Saturday, and it's shown that way for the next couple of weeks. I'm thinking the decent weather is over for the year.



I noticed the 7 1/2" lower pads have a center brace welded in and it looks stock. They are heavier than the 8" pads. Seems strange for a 1/2 ton truck but it is slightly newer, 1989 1/2 ton V6 rear vs. 1991 1/2 ton 22RE rear. Maybe they beefed them up in the newer years?

Yes the U bolts look like they will work with either 1/2 ton leaf spring clamp set. The rust on my 7 1/2 rear U bolts has taken a toll as some of the threads don't look so good on each of them. If I use these I'll eventually get new ones or at least locate some in better shape. I've read they have some top choice stuff but the price of U bolts and nuts from streettacos.com seems a bit high right now.


I'm wondering if the bolt that goes through the stock 7 1/2 leaf springs will cause any problems. I'm guessing not but I haven't gotten that far.

.