On the left, you can clearly see how much larger the 10.25-inch Sterling long-pinion yoke
Fact: This axle is almost an exact copy of the 1st-generation 10.25-inch, but it did receive a larger yoke and pinion with increased spline contact area in an effort to solve problems caused by the smaller yoke/spline of the 1st generation.
Found under: '93-'98 F-250 and F-350
Type: Full-float, semi-float (depending on gross vehicle weight)
Weight (lb., approx): 310 (single wheel full-float), 330 (dual wheel full-float), 258 (semi-float)
Ring gear diameter (in.): 10.38
Pinion shaft length (in.): 10.50
Pinion shaft spline count: 31
Axleshaft spline count: 35
Axleshaft diameter (in.): 1.5 (at the splines)
Hypoid offset (in.): 1.50
Gear ratio range: 3.08-7.17
Normal GAW range (lb.): 6,250 (single wheel full-float), 8,250 (dual wheel full-float), 5,300 (semi-float)
Nominal GCW rating (lb.): 18,500 (single/dual wheel full-float), 17,000 (semi-float)
Output torque maximum (lb-ft): 8,300 (single/dual wheel)
Output torque continuous (lb-ft): 2,000
Weak points: Like the 1st-generation 10.25-inch Sterling, tires 38 inches or taller used in conjunction with 4.10:1 or numerically higher gearing tends to bring on pinion tooth failure due to the decreased pinion size of the higher ratio pinion teeth. This combination also contributes to excess spider-gear wear and failure along with case failure. Like the 1st generation, it is not uncommon to see a case split in half.
Fixes: Switching to a three-spider gear setup will go a long way to address these issues (see the information on the three-spider gear upgrade in the 10.50-inch "Hot Tips").
Hot tip: If you do a lot of towing, use a larger-capacity cover to keep the axle cool. Custom Differentials recommends and sells a finned aluminum unit for this purpose.
Since we 'wheelers can't seem to leave anything stock for long, the aftermarket has responded with a variety of upgrades to make our rigs better. Following are but a sampling of the products available from Custom Differentials for the Sterling 10.25- and 10.50-inch axles.
Aftermarket gears: Yukon Gear, U.S. Gear, Richmond Gear
Limited-slip differentials: Eaton, Ford Traction-Lok (two- and three-spider), Auburn
Locking differentials: Detroit, ARB, Lock-Right