The 1202I (base model axle) and the E1202W are both rated at 12,000 pounds. The E1322W Series is rated at 13,200 pounds. The "I" designates the standard axle width and the "W" designates the wide-trac version of the axle.
The new axles are standard for Peterbilt Models 379, 387, 385, 378 and 362. They are also available for Peterbilt's vocational Model 357 and medium duty Model 330.
The axles feature lightweight, forged integral steering arms with a power rib beam. Two in-line drawkeys with spring washers, a common large diameter kingpin and compressible kingpin inserts help improve axle alignment and durability, as well as improve tire wear by reducing toe change (tire bowing) under load, Peterbilt officials said.
The axles also have a 1.25-inch center drop in the axle beam for greater clearance with the engine oil plan, providing enhanced access for easier servicing.