Comparing (2) Ford 8.8-Inch axles:
- 2010 28-spline Ford 8.8-Inch big bearing from a 2WD regular cab with a 2.3L automatic
- 2004 28-spline Ford 8.8-Inch small bearing
Both are open differentials.
The 2010 differential does not have a tone ring at the ring gear.
For 2010, if you find a big bearing, it isn’t necessarily a 31-spline. I don’t know what a 2010 4WD has.
Comparing a 2004 8.8 28 spline small bearing drum vs 2010 8.8 28-spline big bearing disk (below). Note the ends are very different, and the 2010 has no hole for ring gear tone ring. The 2010 is 1/2″ narrower. 57-1/2″ flange to flange. When you put the disks on it’s 58-1/4″ between wheel mount surfaces.
Above: The 2004 axle has the ABS sensor on differential. The 2010 axle has a tone ring at each wheel. The unused hole in the 2010 axle does not line up where a tone ring would be.
Center of 2010 disk measures 3/8″ thick.
Above: The center thickness of the disks is freakin’ huge at 3/8″. They are approx 1/4″ thicker than drums. So, put the thick disks on the narrow 2010, and it equals the same width (track width) of the 2004 with drums.
The 2010 disks are 11-9/16″ diameter, 3/4″ thick, and vented. That’s a lot of brake power for a regular cab 2WD.
How I measured overall width, the cross pin is inserted between shafts:
Comparing the widths. The blue tape is where the bearing rides, that’s the 2010 axle
Above: The 2004 width measures 58″. The 2010 (with tone ring) width measures 57-1/2″. The 2010 is 1/2″ narrower than the 2004 to compensate for the added width of the disc brakes (2010-2011).
2010 short side axle
2004 short side axle shaft at 27-3/16″
2010 long side axle shaft.
2004 long side axle shaft at 30-1/16″. It’s about 1/4″ longer than the 2010 long side axle shaft at 29-13/16″.