Tamiya 51764 - TRF421X Gear Diff Joints (ball bearing type) replacement and upgrade parts  [51764]

Gear diff joints for TRF421 series

This is an RC-scale gear differential joint set designed for the Tamiya TRF421 family. The package contains 2 pcs of TRF421X gear diff joints (ball bearing type) intended as direct replacements for worn parts on the TRF421X (Item 42391) or as an upgrade option for the standard TRF421 (Item 42384). The joints are steel, ball bearing type, and are used inside the differential to connect the drivetrain while improving rigidity compared with worn or standard stamped parts.

Fit and compatibility are limited to the TRF421 chassis line specified above, so confirm your chassis item code before ordering. When installing on TRF421 (Item 42384), use Item 51762 Ball Bearing Set for Universal Shafts to complete the universal shaft bearing arrangement as noted in the original parts list.

In tuning contexts these steel, ball-bearing joints are selected to maintain drivetrain alignment and reduce play caused by worn diff internals. They are a focused hop-up part for drivers who need reliable replacement components that match TRF421 series geometry.