31 spline 8.8 identification.

[Dantheman1540]

Looking to get a 31 spline 8.8, with 4.56, and at minimum a torsion style posi, but would consider an auto locker as well, for my 94ranger.

I know there are many ways to skin this cat and I have what I’d consider a fairly high mechanical know how when it comes to axles so no labor cost would be involved in this project. I’d love to find an FX4 level 2 axle and just swap it in but finding one has proved impossible in the last two weeks of looking. I’ve searched car-parts.com, local LKQ, eBay, and local market places with no luck.

So I’m now considering an expo rear axle with a torsion diff and slapping 4.56s as well as swapping mounts, although I don’t really want to do a bunch of axle welding. My Hobart 140 doesn’t have that much power behind it and I’m not a “pretty” stick welder lol.

Anyone else have any good options that are affordable? Or a good place to search for an FX4 level 2 axle?

 

[sgtsandman]

An Expo axle with the spring perches flipped is probably going to be your least expensive option. An FX4 axle would be a dream but they are so uncommon...

 

[Dantheman1540]

An Expo axle with the spring perches flipped is probably going to be your least expensive option. An FX4 axle would be a dream but they are so uncommon...

That’s the reality I’m coming to terms with. I called a dozen places that claimed to have one and they all lied lol.

 

[sgtsandman]

That’s the reality I’m coming to terms with. I called a dozen places that claimed to have one and they all lied lol.

To them, an FX4 is an FX4, is an FX4. They don't know the difference other than the sticker on the side of the truck.

 

[Dantheman1540]

To them, an FX4 is an FX4, is an FX4. They don't know the difference other than the sticker on the side of the truck.

Very very true

 

[Dantheman1540]

The explorer posi units are a clutch style limited slip not a torsion style right?

 

[Dantheman1540]

If I go the expo route I may just leave it spring under. Grab a set of F65a springs and a longer shackle to make up the height. Need to replace leaf bushings and stuff anyway and the springs are cheaper than doing the perch swap. Spring under would also help with axle wrap that I don’t currently have, but something I despise.

 

[scotts90ranger]

Welding spring pads on isn't rocket surgery, your 140 welder is fine for that... same with shock mounts.

Personally I might look for an open diff Explorer axle and throw a lunchbox locker in there for cost savings, I put my aussie locker through a lot of abuse before it died... but 2 years ago bought a Yukon Grizzly locker for $500 on Amazon... if you have to set up gears anyway... I've been running Nitro gears for a decade but only 30k miles or so but a lot of abuse and they've been fine...

 

[scotts90ranger]

Around here Pick A Part junkyards have a half off weekend pretty much any big holiday so you can get any axle for like $100 or so so that cuts into looking for anything fancy...

 

[alwaysFlOoReD]

You might have better luck looking for a "Torsen" diff, not "torsion".

 

[Dantheman1540]

You might have better luck looking for a "Torsen" diff, not "torsion".

Dang you got my illiterate butt.

Around here Pick A Part junkyards have a half off weekend pretty much any big holiday so you can get any axle for like $100 or so so that cuts into looking for anything fancy...

Any axle is $190 at my local yard, they don’t even check what’s in it, or at least haven’t my last few axle snatch trips.

Welding spring pads on isn't rocket surgery, your 140 welder is fine for that... same with shock mounts.

Personally I might look for an open diff Explorer axle and throw a lunchbox locker in there for cost savings, I put my aussie locker through a lot of abuse before it died... but 2 years ago bought a Yukon Grizzly locker for $500 on Amazon... if you have to set up gears anyway... I've been running Nitro gears for a decade but only 30k miles or so but a lot of abuse and they've been fine...

I agree welding pads isn’t awful, but it means I have to have the truck apart for mock-up of the perchs and to set pinion angle. Id prefer to have the axle 99% ready to swap in so it’s a one day affair.

I may very well break down during the parts gathering portion of this project and get a nice locker, but I think a posi would be good enough for my use of this truck. Does your grizzly lock and unlock loud and harshly on the street?

I think all in if I do the expo axle spring under with f65a springs and whatnot, I’ll be under $750 if I don’t spring for a locker of course.

 

[alwaysFlOoReD]

I converted a spring over to spring under using bolt on scrap metal I had. Its somewhere in my racetruck build thread.
There are after market similar for sale.

 

[scotts90ranger]

The grizzly is much more pleasant to drive than the aussie and the aussie wasn't that bad compared to other ratcheting lockers I've heard...

 

[Dantheman1540]

I converted a spring over to spring under using bolt on scrap metal I had. Its somewhere in my racetruck build thread.
There are after market similar for sale.

I think I’ve seen that before, however I like the idea of going spring under to help with axle wrap in the future. I’m sure going from 3.27s/open to 4.56/locked is gonna be very different in terms of first gears ability to spin the tires.

The grizzly is much more pleasant to drive than the aussie and the aussie wasn't that bad compared to other ratcheting lockers I've heard...

I’ll have to keep an eye out for one, I’ve used just about every type of posi/locker in the past except a good quality auto locker. I have a factory G80 in my stick shift Tahoe. It’s in a semi floating 14bolt and it does well in straight line traction scenarios such as pulling a trailer up a wet grassy hill, or through thick sand. It sucks at locking up when trying to do donuts, burnouts, or slides tho. I think it’s just about worn out, but it’s somewhat given me a bad taste to the unpredictability of auto lockers.

This project will be over several months so maybe I can catch a grizzly on Black Friday!

 

[Dantheman1540]

New question has arose in my hunt for a rear axle. Is there any other identifying options that would tell me if the axle is 31 spline? I have located an 8.8 with door code 97 (open/4.10s) and the yard sales guy says it’s a 31spline with a locker, but I don’t want to drive an hour and a half to find out I was lied to. I don’t care a ton if it’s an open carrier or factory posi, but I absolutely want it to be 31spline.
The truck it’s out of is an 03 Edge, 3.0, auto, 2wd. https://imageappky.car-part.com/image?seller=3992&partsourceid=3992&partGUID=3992-1-520201&vehicleGUID=3992-1-V7370&display=2003 Ford Ranger Rear Axle Assembly-Stock# 14428