29 or 31 spline?

[66 Ranchero]

i have an 04 FX4 and i was curious if the rear axles were 29 spline or 31 spline

 

[wrecking-crew]

Newer vehicles have the 31 spline.

 

[66 Ranchero]

cool thanks! i bent and axle shaft gettin run off the road by a cement truck and kissed a curb at 60! so i was gonna hit up a junkyard this weekend. thanks again!

 

[66 Ranchero]

the rear end is an 8.8 aint it?

 

[Sunk]

Yes you have an 8.8.

 

[66 Ranchero]

thats what i thought, thanks!

 

[Mac]

I believe you would have the 28 spline axle. The tech library has this to say:
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."
I forget what the diameter of the axle tubes are, maybe the 28 is around 2.75 and the 31 spline is like 3.25. Easy way to tell if you know the tube size, I just can't remember right now.
Dave of the Nord

 

[06RangerXLT]

pull your axle, count the splines....

 

[Mac]

pull your axle, count the splines....

Let me think about that - five mins to crawl under and measure it, no cost.
Pull an axle -maybe an hour, couple qts of gear oil. Kind of a tough call!
Dave of the Nord

 

[85_Ranger4x4]

I believe you would have the 28 spline axle. The tech library has this to say:
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."
I forget what the diameter of the axle tubes are, maybe the 28 is around 2.75 and the 31 spline is like 3.25. Easy way to tell if you know the tube size, I just can't remember right now.
Dave of the Nord

Didn't the 28 spline use the same axle shafts as a 7.5 too?

That would really open up options for the OP...

 

[06RangerXLT]

Let me think about that - five mins to crawl under and measure it, no cost.
Pull an axle -maybe an hour, couple qts of gear oil. Kind of a tough call!
Dave of the Nord

hes replacing it because its bent. gonna need to do those things anyways.

 

[06RangerXLT]

Didn't the 28 spline use the same axle shafts as a 7.5 too?

That would really open up options for the OP...

ford some reason i think the shaft size is different, though i could be wrong. i thought i read somewhere it was, one of the reasons i avoided a 7.5 when i was looking.

 

[fastpakr]

I'm pretty sure all FX4's have 31 spline axles, but only the L2's got the Torsen. Not absolutely sure, though. AllanD, do you know?

 

[06RangerXLT]

ok, how about you give us the door code. that will tell you exactly what it is

 

[adsm08]

ford some reason i think the shaft size is different, though i could be wrong. i thought i read somewhere it was, one of the reasons i avoided a 7.5 when i was looking.

The bearing diameter of the 7.5 and the 28 spline 8.8 is the same, inside and out. Thus it follows that the shaft diameter would be the same.

For some reason I'm thinking the shaft length is different.

Let me find a tape and I'll go out and measure my 8.8s since I have one of each in the garage.