This friction disc is the component that transmits torque through the front axle differential or final drive, allowing the axle to lock or slip as needed. It sits between the pressure plates in the axle housing; when engaged, it transfers drive force to both wheels, and when disengaged, it permits differential action. A worn disc reduces clamping force, leading to chatter during engagement or unintended slipping under load. The original manufacturer machines the friction material to the same thickness and surface finish as the original assembly, so the clutch pack's engagement timing and torque capacity are preserved. On reinstall, inspect the opposing steel plates for scoring and replace them if worn.