Tamiya 51767 - TRF421X Gear Differential Unit Set  [51767]

TRF421X gear differential unit

This gear differential unit set is a direct replacement component for the TRF421X series where the product name indicates intended fitment. It is a gear-type differential designed for 1/10 scale touring car use, serving as the internal differential assembly that manages torque distribution between drive wheels.

The unit's role is primarily maintenance and tuning: swap the differential when wear affects handling, or when changing differential behavior is part of setup adjustments for handling balance on track. Installation requires basic disassembly of the centre gearbox and attention to gear mesh and bearing seating to maintain smooth operation.

When replacing this assembly, inspect associated bearings and spur/pinion contact for wear, and verify torque screw settings on the gearbox to avoid unintended preload on the differential. Use standard RC workshop practices and correct tools for secure fastening.

This replacement differential unit is intended as a direct spare for TRF421X-based 1/10 touring cars, useful for restoring original drivetrain function or adjusting differential behavior as part of setup work.