When we were at centrailia Jeff and I were discussing ranger axel sizes. From my understanding V6 rangers have a 8.8 inch axel. While 4 bangers have the 7.5 inch axel. It dawned on me later is there a difference in axel spline or size between an fx4 level 2 and a none FX4. If so what is the difference ? Maybe I should just ask the question how do I know what axel, and splines, I have ?

Jeff what is your screen name anyway ?

 

im pretty sure all the 4 cyls come with the 7.5 axle. low end 6 cyls also have the 7.5 as well, high end 4.0 and 4x4s have the 8.8 the 8.8 has 28 spline axles i think, while the FX4 axle with the torsen diff has 31 splines. if im wrong its because i have ford 9 inch numbers rolling around in my head.

to see what you have, clean off the tag hanging off the diff cover, and tell us what it says. on yours it should say somewhere 88 4L10 for 8.8 4.10 LS

 

Some 6 cylinders (3.0's) have 7.5 axles too, particularly the standard cabs, but some extended cabs got them also.

Yes, the FX4 Level II has 31 spline axle shafts which are thicker than the shafts on the 28 spline models and about 30% stronger. Also, the 28 spline axle tube is 2.75" in diameter, while the 31 spline axle tube is 3.25" in diameter. Another difference is the axle bearings: 28 spline use 2.25" diameter bearings, 31 spline use 2.5" diameter bearings.

Both 28 and 31 spline axles use compatible ring and pinion systems. The carriers are the same also I THINK, but the splining and size of the gears that go on the end of the axle is different. Could be the 31 spline carriers are different -- don't know.

From 2003 on, the FX4 that is NOT the level II has the 28 spline rear.

7.5 and both 8.8 axles have compatible braking systems. There are two drum sizes used in Rangers. Most later ones and most 4x4's have 10" rear drums but earlier Rangers and some 4x2 Rangers have only 9" rear drums. I'm uncertain of the cut off years, or how Ford decided who got what.

 

john im pretty sure that the carriers would have to be different for the different spline axles. the ring and pinion should be the same however.

 

No, they wouldn't have to be different. They just need a big enough hole in each end for either axle, and appropriate bearings. But they probably are different -- I just don't know.

 

yeah i guess its possible if the 28 spline axles were longer, and the 31s shorter, than the carrier could be the same, but, the 28 spline axle would have to be as no thicker than the thinnest point of the 31 spline, in the splines, if you know what i mean. also, you would only be using half of the available space in the carrier to hold the axles, which would be silly as far as a strength standpoint.

but like you said, i dont know either, just rationalizing

 

damn Mr. Griggs knows his stuff.....

 

Some general info about late model Ranger axles:

All 4x4s have 8.8.
All 4.0L have 8.8.
All Trailheads have 8.8.
Beginning sometime in the 2002MY, all Edges have been equipped with 8.8, regardless of engine size or drive.

2WD XL, XLT 2.3L have the 7.5
2WD XL, XLT 3.0L, regular cab or supercab, have the 7.5.

All have 28-spline axle shafts except the 2002 FX4 and the 2003+ FX4 LII. These have a unique axle assembly with larger tubes, larger bearings, larger 31-spline axle shafts and a Torsen differential.

The Torsen is a gear type limited slip differential available in the LII-type Rangers only. Most other V6 Rangers have Ford's Traction Lok limited slip available as an option. The 2003+ FX4 Off Road has Traction Lok standard.

 

Beauty! Good info.

And I posted on those FX4 bearing sizes. Those larger (2.5") axle bearings are the same as on F-150's, and 31 spline Explorer axles.

 

I saw that, John. I had already answered the same question earlier for Ben on G-E. So I copied that post here more or less intact, just in case it might do someone some good.

 

lol! Yes, I had to get that stuff together purely as a practical matter when I went to order a rebuild kit for the rear and they guy asked me, "what size axle bearings?" and I had no idea!

 

One thing I can tell you for sure: the carrier BEARINGS are the same. When you get the rebuild kit it comes minus the axle bearings and the same bearings are used for the 31 and 28 spline for the carrier. Then you get the appropriate axle bearing as an "extra". You have to press the carrier bearings on the carrier.

 

Hey Ben its me Jeff. :)

Anyway...I'm reading all this the whole while thinking...damnet SCREWED again not getting the "coolest" Ranger available and now I have this silly 28 spline axle...
Maybe I'll call around the yards and find a wrecked FX4 LII if I'm lucky and swap mine out!

 

i bought my truck used from a dealership and on the description it said fx4 offroad package. truck was built in september of 2001. how do i determine if my truck is a true fx4 or not? itd be nice to know ive got 31 splines and i wouldnt be telling a lie if i slapped an fx4 sticker on there.

 

One way would be to measure the OD of the rear axle tubes. The 2002 FX4 should have the larger 3.25" tubes that enclose the 31-spline axles.

Also, since your truck is a manual, it would also have a manual transfer case shifter. If you have a 4x4 switch on the radio bezel, it is not a 2002 FX4 manual. A 2002 manual FX4 should have 2 chrome shifters that look like this: