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8.8 29 to 31spline

RoamingCanuck

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Hey guys,

I think I'm getting some misinformation online and I was hoping someone could clear it up for me.

I have a 8.8 29 spline at the moment, its 4.10 gears which is acceptable for me thus far but its open diff. Instead of dropping 500$ on a lunchbox locker for the 29 spline and having no control over it I'd like to upgrade it to a 31 spline.

The local wrecker has a explorer 8.8 with 31 spline and 3.55 gears:)sad:) that I'd like to pillage for shafts.

Now obviously just the shafts wont work unless you change the carrier so I was going to get an ARB to go with the JY 31 spline shafts. However some people are saying on threads thats all you need to change and others are saying no you need to change bearings too?

So whats the deal? What needs to be changed to switch over to 31 spline? Or is it more work than its worth and I should just do a lunchbox or ARB for the 29 spline?

I'm only rocking a little 2.3L 4x4 so its not like I'm putting out huge power or moving huge wheels, 31 spline isn't a necessity, I just thought if I'm dropping 1200-1500$ on an ARB, if its an extra 60 bucks for some shafts I may as well get the 31 spline strength right?
 


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Have a read here and it will start to make sense: http://www.therangerstation.com/tech_library/Ford-8_8-axle.shtml

Ranger 7.5" and 8.8" used the same axle size, 28spline/1.21" diameter, so same seal and bearing.
In 2010 Rangers got larger axle Tubes on the 8.8", axles stayed the same.

Rangers with Level II off-road packed did have 8.8" with 31 spline, and limited slip

Explorer 8.8" used 31 spline and 1.32" diameter axle, also 1.5" wider on each side, 3" overall wider than 1983 to 1997 Ranger, 1998 Ranger axles were wider but still 1" less than Explorer width

If you got the whole explorer rear end you can swap over and use your 4.10 ring/pinion on that
Other than that you won't be getting 31 spline
 
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adsm08

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The parts needed to change from a 28 spline 8.8 to a 31 spline 8.8 are as follows:

A 31 spline 8.8. Proper u-bolts, plates and shock tabs are also good to have.

The 31 spline has bigger tubes. The bearings won't fit the 28 spline tubes.
 

Captain Ledd

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Honestly, the 31 spline shaft swap is a bit overrated. And you'e looking at someone who has a 31 spline Explorer 8.8 under his 2.3L powered rig. The 28 splines are plenty strong, especially if you're not turning huge tires. They're better steel than a comparable Dana 44.

I only built mine because I had an extra axle around, and adding up the costs, it was only about $20 difference between the 7.5" and the 8.8", excluding locker options. Full brakes, all bearings and seals, everything.

Unless you get custom shafts or hold out for the FX4 Level 2 axles, 31 spline in a Ranger package is difficult.

But since you're pulling the carrier, you could also swap over your 4.10's to the Explorer axle, and as long as you match the pinion depth and backlash to the original 4.10's, it should work pretty well. But that can get kinda tricky, and I wouldn't advise it if it's your first go around with R&P's.

Since you're no where near the stress limit on those shafts, I'd rock the 28 spline ARB, all you have to double check is the ring gear backlash (make sure it's the same), and keep on drivin'.
 

RoamingCanuck

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Honestly, the 31 spline shaft swap is a bit overrated. And you'e looking at someone who has a 31 spline Explorer 8.8 under his 2.3L powered rig. The 28 splines are plenty strong, especially if you're not turning huge tires. They're better steel than a comparable Dana 44.

I only built mine because I had an extra axle around, and adding up the costs, it was only about $20 difference between the 7.5" and the 8.8", excluding locker options. Full brakes, all bearings and seals, everything.

Unless you get custom shafts or hold out for the FX4 Level 2 axles, 31 spline in a Ranger package is difficult.

But since you're pulling the carrier, you could also swap over your 4.10's to the Explorer axle, and as long as you match the pinion depth and backlash to the original 4.10's, it should work pretty well. But that can get kinda tricky, and I wouldn't advise it if it's your first go around with R&P's.

Since you're no where near the stress limit on those shafts, I'd rock the 28 spline ARB, all you have to double check is the ring gear backlash (make sure it's the same), and keep on drivin'.
Awesome thanks. Thats what I was kind of hoping to hear. I didn't really want to worry about swapping shafts if I didn't really need to.

ARB and then reuse my current R&P it is. Though, I'll be getting a shop to do it. It would be fun to try it but I don't want my handy work leaving me 2000km from home broken down. lol
 

pjtoledo

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search A31-93RANG for 31 spline carrier in a 28 spline housing
 

thcscubajohn

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Honestly, the 31 spline shaft swap is a bit overrated. And you'e looking at someone who has a 31 spline Explorer 8.8 under his 2.3L powered rig. The 28 splines are plenty strong, especially if you're not turning huge tires. They're better steel than a comparable Dana 44.

I only built mine because I had an extra axle around, and adding up the costs, it was only about $20 difference between the 7.5" and the 8.8", excluding locker options. Full brakes, all bearings and seals, everything.

Unless you get custom shafts or hold out for the FX4 Level 2 axles, 31 spline in a Ranger package is difficult.

But since you're pulling the carrier, you could also swap over your 4.10's to the Explorer axle, and as long as you match the pinion depth and backlash to the original 4.10's, it should work pretty well. But that can get kinda tricky, and I wouldn't advise it if it's your first go around with R&P's.

Since you're no where near the stress limit on those shafts, I'd rock the 28 spline ARB, all you have to double check is the ring gear backlash (make sure it's the same), and keep on drivin'.
Who makes custom shafts will Richmond do it for me?

Sent from my SM-G950U using Tapatalk
 

Captain Ledd

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I don't know, why don't you call Richmond?

(sorry for the smart ass response, but really tho)

Suppose they do, what are you going to do about the bearings? I haven't measured the journal dia's, hopefully the 31 spline stuff will fit through them.
 

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I have to agree about the 28 spline 8.8. Yes the 31 spline is stronger by a considerable amount however...... plenty of guys have wheeled and raced 28 spline 8.8s and have had good success. Now if you are building a 400+ horsepower LQ9 powered ranger with sticky tires on a powerglide with trans brake by all means opt for the 31. However consider most rangers have under 200hp and run smaller then 31 inch tires it's simply a waste. Heck even the 28 spline 7.5 can handle a fair amount of abuse.
 

turbo91xlt

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Hey guys,

I think I'm getting some misinformation online and I was hoping someone could clear it up for me.

I have a 8.8 29 spline at the moment, its 4.10 gears

I'm only rocking a little 2.3L 4x4
Are you sure you have an 8.8? All 2.3 4x4s came standard with a 4.10 geared, 28 spline 7.5 axle.
 

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