The AAM 11.5” TracRite Helical Differential Case, No. 40099548, was designed for the 11.5” rear axle used in 3/4-ton and 1-ton 2003-2012 Ram, 2001-2011 Chevy Silverado and GMC Sierra trucks. Each assembly is built to OEM specs because they are the same units made for OEM production use. The torque bias is proportional to the throttle, providing a smooth application of torque to the wheels. Because the differential uses helical gears, there are no clutch plates to wear and no friction additives needed, according to the company.