This friction disc sits inside the gearbox of the host tractor, where it transmits torque between rotating and stationary elements during gear engagement. It is one of several discs in the clutch pack that, when compressed by hydraulic or mechanical pressure, locks the selected gear set to the output shaft. Wear on the friction material reduces clamping force, which leads to slipping under load and delayed or incomplete gear engagement. The disc is manufactured to the original thickness and friction-characteristic specification so that the pack’s total stack height and spring compression remain within design limits. On reinstallation, verify that all discs in the pack are within service thickness and that the separator plates are free of scoring.