If you’re driving a late-model GM or Dodge heavy-duty truck, then chances are you have a big rearend. Now don’t take that as an insult. We’re talking rear axles here. Those found under the 3⁄4- and 1-ton GM and Ram trucks are made by American Axle Manufacturing. These trucks have three different rear axles based on ring gear diameter: the Dodge 101⁄2-inch, the GM 101⁄2-inch found in gas 3⁄4-tons, and the 111⁄2-inch found in both manufacturers’ diesel and 1-ton trucks.
These three axles are all massive and ideal for large tires in the 37- to 44-inch range. They come with disc brakes, and are all full-floaters, but with this size come weight and ground clearance issues. We have been noticing a trend of aftermarket axle companies developing larger axles for the off-road market, but we’ll delve into that in the future. For now we’ll give you some insight on why you might (or might not) want an AAM axle under your next 4x4 project.