Every diesel-powered pickup sold in the United States for the last 10 years has a full-floating rear axle. Fords currently use a 10 1/2-inch axle made in a plant in Sterling Heights, Michigan-so most people refer to this axle as the Sterling 10 1/2-inch. In F-350 dual rear-wheel trucks, Ford steps up to the 11 1/4-inch ring gear Dana 80 for more weight capacity. Dodge, on the other hand, used the Dana 70 ('89 to '93) and Dana 80 ('94 to '02) axles. Then in 2003, Dodge switched to an American Axle & Manufacturing (AAM) 1050 and 1150 (101/2- and 111/2-inch ring gear diameters, respectively) when it redesigned its HD trucks.
General Motors has only used two rear axles in its 1-tons over the last 17 years: the 10 1/2-inch-diameter ring gear 14-bolt ('92 to current) and the 11 1/2-inch-diameter ring gear AAM 1150 14-bolt ('01 to current). Why has GM stuck with the 14-bolt for so long? Because it's a proven design that can handle an enormous amount of torque.
General Motors manufactured the 14-bolt axle in-house until 1994 when American Axle & Manufacturing (AAM) was spun off as its own independent entity to produce drivetrain and suspension components. In this article we're focusing on the 10 1/2-inch 14-bolt that was used behind the 6.2L and 6.5L GM diesels, but there's no reason it couldn't handle the torque of the modern Duramax engine. In fact, using the 10 1/2-inch 14-bolt to replace the 111/2-inch ring gear 14-bolt found in '01-to-current trucks gives you the option of running an ARB Air Locker, various limited slips, a Detroit Locker, a spool, and axle ratios from 3.21:1 to 5.38:1. And keep in mind the old 10 1/2-inch axle uses the same diameter axleshafts as the new 11 1/2-inch ring gear AAM 1150. DP
 General Motors designed the...  General Motors designed the 10-1/2-inch ring gear 14-bolt axle for the '73 Chevrolet and GMC 1-ton trucks, but it's still in use today in gasoline-powered 2500HD pickups and Suburbans. The 14-bolt axle features a cast-iron center section with a bolt-in pinion support, 3-1/4-inch-diameter press-fit steel tubes, and welded-on spindles for the full-floating wheel hubs. |  One thing the Ford 9-inch...  One thing the Ford 9-inch and the 1-1/2-inch larger 14-bolt axles have in common is this third pinion bearing (arrow) that ensures the pinion gear and the ring gear stay meshed regardless of how much torque is applied. None of the other axles found in 1-ton diesel trucks feature this third bearing. |  The 14-bolt axle comes from...  The 14-bolt axle comes from the factory with an open differential, Gov-Loc locking differential, or even a Detroit Locker in military applications. For ultimate strength and versatility however, we opted for the ARB Air Locker. The ARB works just like a conventional open differential (perfect for on-road driving) until you flip a dash-mounted switch and an internally air-actuated mechanism locks both axleshafts together, which is ideal for drag racing, sled pulling, and off-road use. |