29 or 31 spline?

[adsm08]

Ok, the 28 spline is ~9.5' in circumference. The 31 spline is ~10.25' around the axle tube.

 

[Tominator]

Look at the housing diameter inside of the drum or rotor near the bearing.

If the housing tapers in to the backing plate it is 28 spline. If there is no taper the spline size is 31.

Many Mustang drag racers stick with the stock 28 spline rear ends but when you approach 500HP this becomes a weak link.


More so if you put drag radials in the mix, but there are some very fast Mustangs with 28 Spline axles and 4 bolt wheels putting out lot's of torque and HP!

When I built my Ranger there were no options for a Explorer 3rd member change so I opted for Strange Engineering axles.

I would not trust them for a full power launch with drag radials, but they will take a lot of abuse and the spline count would be the least of the worries.

 

[66 Ranchero]

the door sticker says R7 under axle

 

[06RangerXLT]

Are you still driving the truck? Or is it parked till you get a new axle? You can either take your vin to ford and find out for sure, or pull the acle and count. Unfortunately without looking at it, we are all just guessing. You have a LS 8.8 4:10. But again, I can't say for sure it's 31, and if I were you, I'd never trust it till I counted myself.

 

[85_Ranger4x4]

Per the tech library:

2) The 1990 & up 4.0-liter Rangers are ALWAYS equipped with the 8.8-inch 28-spline rear axle.

3) 1998-up 4x4 supercab Rangers regardless of powerplant are frequently equipped with 8.8-Inch axles

4) The FX4 Ranger was introduced in 2002 and always came with 4.10 gears only. The 31-spline Torsen 8.8-inch axle came only with the 2002 FX4 and 2003-up FX4 Level II and more recently was a separate option. The 2003-up FX4 (non-Level II) is essentially the same as the 1998-2002 Off-Road except that a regular Ford limited-slip in a regular 8.8-inch was included.

Swapping in an 8.8-inch 28-spline Ranger axle for the original 7.5-inch axle provides (according to Ford) a 35% increase in strength. But this strength increase refers to the greater strength of the gears and carrier bearings (Pinion bearings, axle bearings and axle shafts are exactly the same)

There is no difference between 7.5 & 8.8 axle shaft lengths provided you stay in the same year window.

The early 1983-1992 Ranger axles are 1-inch shorter than the 1993-up pieces (Both sides). This means that the an entire Ranger axle assembly from 1993-up is 2-inches wider than 1983-1992.

http://www.therangerstation.com/tech_library/Axles.html

31 splines have 3.25" diameter axle tubes, that is all you really need to know to tell what you have.

 

[06RangerXLT]

The 2003-up FX4 (non-Level II) is essentially the same as the 1998-2002 Off-Road except that a regular Ford limited-slip in a regular 8.8-inch was included

there ya go, its a 28.

but honestly, dont order or buy anything till you count the splines on your axle. for all you know, the rear end could have been upgraded, much like mine.

 

[85_Ranger4x4]

but honestly, dont order or buy anything till you count the splines on your axle. for all you know, the rear end could have been upgraded, much like mine.

No need, just measure the axle tube. The axles shafts won't interchange with the housings, so measure the housing.

Then you don't have a dead horse to deal with until you get parts.

 

[Downey]

ALL FX4 RANGERS HAVE 31 SPINE AXLES.


if you think im wrong go measure you axles tubes are bigger on the fx4 i think the 28 splines are 3 inchs and the 31 spine are 3.25 inchs but in other words if your axles tubes are bigger than 3 inches you have a 31 spine rear.

 

[Mac]

ALL FX4 RANGERS HAVE 31 SPINE AXLES.


if you think im wrong go measure you axles tubes are bigger on the fx4 i think the 28 splines are 3 inchs and the 31 spine are 3.25 inchs but in other words if your axles tubes are bigger than 3 inches you have a 31 spine rear.

You have just proven our great tech library wrong then! My 28 measures between 2.75-2.875.

 

[adsm08]

Then you don't have a dead horse to deal with until you get parts.

If he bent the shaft then he already has one. Driving with a bent shaft can damage the housing and should not be done.

if you think im wrong go measure you axles tubes ....

Why are we still debating the size issue. I have already solved this one. The only difference is that you guy are debating the diameter and I took a measurement of the circumference and posted it. But if any of you remember basic geometry, diameter and circumference are directly related. The 31 spline is larger, and so you can get a definitive answer about which axle it is by measuring that.

 

[Mac]

Most of the problems up here are with the wheel mounting flange getting bent from just what the OP described. If the axle is truly bent, I'd sure look deeper for any other damage.
Adsm - think a lot of the people really don't look at all that has been posted but jump right in anyway. That measurement thing has been brought up 3-4 times.
Dave of the Nord

 

[85_Ranger4x4]

If he bent the shaft then he already has one. Driving with a bent shaft can damage the housing and should not be done.

It has already been driven on. I meant that you could move it to mow around it or get the wifes car in for a storm if you waited to yank it all apart until you had the part in hand to fix it. Also less chance of the housing getting contaminated depending on the work enviroment.

It seems whenever I get into a big project like that somehow part shortages ensue, difficulties arise and I get in trouble for tying up prime real estate in the garage.

 

[adsm08]

It seems whenever I get into a big project like that somehow part shortages ensue, difficulties arise and I get in trouble for tying up prime real estate in the garage.

That is one of the reasons we don't park in the garage.

Also because our garage isn't really big enough.

I am kinda hoping to have enough space in the new one to have two projects and a parked vehicle though.

 

[gribly]

I know for a fact my dad's '05 LII has a 3.25, it matches my Navajo's rearend, too.

 

[66 Ranchero]

sorry if i mislead anyone but Mac is on it. its the wheel mounting flange that is bent not the actual shaft itself. sorry thats what you get when you give a Seabee mechanic a computer lol it doesnt really matter now since i am currently deployed again, this time to Africa tho. when i get back i plan on a SAS and i will upgrade the rear end anyway. thanks again for all the help!