TRF421X Compatible Knuckle Arm for 42391 - Tamiya 9803566  [9803566]

TRF421X steering knuckle details

Shown as Tamiya part 9803566 and linked to the 42391 TRF421X reference, this knuckle arm is intended as a front steering replacement for 1/10 touring car builds that use the TRF421X layout.

As the steering pivot, the knuckle arm conveys steering motion to the wheel hub and plays a role in camber change and steering feel. Replacing the knuckle is a common maintenance or tuning step on TRF421X cars to correct wear or alter transient steering behaviour.

Installation requires removing the wheel and hub carrier fasteners, detaching steering linkages and retainers, fitting the replacement knuckle arm, then reassembling with specified torque values and securing all retaining clips or set screws. Always validate free hub rotation and check wheel alignment before operating the vehicle.

Tuning note: swapping the knuckle can influence toe characteristics under compression and overall steering response; proceed with controlled adjustments and track evaluations. Inspect related components such as bearings and linkage hardware for wear when performing the swap to maintain consistent handling.