TRF420X Stiffener Nut for Chassis Rigidity - Tamiya 9803402  [9803402]

Purpose and fitment of the stiffener nut

This Tamiya 9803402 stiffener nut (part no. 42382) is a replacement threaded fastener designed for TRF420/TRF420X hop-up assemblies. It serves as a locking element for chassis stiffener components, retaining preload and alignment when you adjust chassis stiffness. The focus here is on fit and tuning function rather than exact dimensions.

Use the nut where the chassis layout requires a locking or reinforcing fastener for a stiffener plate or brace. When swapping stiffener plates, adding reinforcement inserts, or testing chassis flex, this nut secures the assembly position and prevents movement that can upset handling balance. Apply standard workshop practice for tightening, avoid over-torquing near composite or thin aluminium parts, and check mating threads and seating surfaces before reuse.

For drivers focused on setup, this nut affects mechanical connection points rather than suspension geometry or electronics. Keep spare common fasteners on hand and monitor thread wear if you change hop-ups frequently.