evanw66

I was hoping someone could clear up a few questions I have about rear axles. I already read the info I could find on them.
The truck is an '87 2WD 5-speed. This truck sees alot of abuse. The axles needs attention really soon. I want to upgrade to lower gears and a locker. Should I:
Get a 8" 4runner axle?
Will this bolt into place of the 7.5"?
Would the 3rd member from an 8" bolt into a 7.5"?
Or should I just rebuilt the gears in the 7.5" and add a locker?
On a related note, if I bolt a 4runner axle into my truck, (assuming this is possible without too much fabbing) Could I stick the 5 lug axleshafts from the old axle into it so that I could have 5 lugs all around rather than 6 on the rear and 5 on the front?
Any help in this is very appreciated; TIA!

upndair

If you're not doing any 4wheeling (sounds like you have a 2wd), I'd stay with rebuilding the stock axle. You won't break it.

evanw66

Just cuz it's 2WD dosen't mean it spends alot of time on paved roads.

upndair

It may not spend all the time on paved roads, but in reality, hard paved road driving can be tougher on the rear end than off road driving due to the high traction gradient.

If you're not locked, running a bigger engine and large tires, your stock rear end will be more than strong enough.

evanw66

Hmmm, ok, but...
I DO want to add a locker and 30" tires. (I'm planning on getting Baja Concepts 3.5" lift)
Still think it would be better to just rebuild the stock rear end?
Thanks for the replies.

upndair

I'd add an LSD rather than a locker. 30" tires won't make any difference to your strength.

What kind of abuse do you plan on doing with your truck? Why do you want a locker?

evanw66

I'm willing to consider an LSD for the rear. I was originally thinking detroit locker, but that would probably be overkill. Do you know of any good LSDs that are reliable and durable? That's what I'm going for.
Any way, the truck is a daily driver/ weekend warrior. I follow my friend's 4x4s on the logging roads, and some rallying in the deserts. I can usually get through most of the trails, but have had to get pulled through some sections that I'm positive 2 rear driving wheels and a mild lift could have gotten me through.
Thanks again for trying to sort me out here.

Mytyota

If you want to lift the rear, get a 4x4 axle. On a 2 wheel drivethe springs are under the axle and on a 4 wheeler the springs mount on top of the axles.that would give you about 4"s of lift. your axles sould fit in either axle as long as its a rear end from an 86 or newer, 85 and older are narrower.

upndair

The Detroit True Trac is an excellent option. It's a gear driven LSD that doesn't have the problems of a clutch driven LSD which wears over time. It's very durable and reliable.

I ran them both in the front and rear of my 4runner at one time. The performed flawlessly and I did notice a significant improvement.

evanw66

So, I can put the 2WD axleshafts in the 4WD axle housing? That would be great news. Can you tell me if the spring perches line up for the SOA 4WD axle? I mean, are the rear springs the same distance from each other to make it a "bolt-in" swap? I don't know how to weld, and would like to avoid if possible the added expense of paying someone to re-locate the spring perches.
I can get an axle from a 91 4Runner for $150. If the springs will match up between it and my truck and the axleshafts will swap over, I'll go for it!
BTW, I like the sounds of that Detroit TruTrac....

Mytyota

the distance between the spring perches is the same between 2by and 4by, make sure you get the u-bolts and plate. The true trac's a good deal.

evanw66

What if I tried to shove an 8" thrid member into a 7.5" axle housing? Is this even possible; has anyone tried this? And would the 7.5" axleshafts fit into it? If it was possible, it may be my cheapest/easiest upgrade. thanks

upndair

I don't think this will fit.