Spline count

[gandrimp]

Is this 100% correct?

Is my rear 8.8" axle 28 or 31 spline?
Check the diameter of your axle tube next to where the leaf spring perch is welded:
2.75" = 28 spline
3.25" = 31 spline

I have an OX locker in my future and my housing measures 3 1/4". So is it safe to say I have a 31 spline axle? TIA

 

[Sasquatch_Ryda]

2003 fx4? Yes 31 spline

 

[RonD]

Good read here on the 8.8" Ford axles: http://www.therangerstation.com/tech_library/Ford-8_8-axle.shtml

Ford Ranger 8.8-Inch Axle versus Ford Explorer 8.8-Inch Axle

All 8.8-Inch Ford Explorer axles use 31-spline axle shafts.
All 8.8-Inch Ford Ranger axles use 28-spline axle shafts (except FX4 and FX4 Level II which use 31-splines).

FX4 Level II used Torsen axle, it used gears for limited slip, standard Ford L/S axle used clutch plates