Tamiya 3404174 - Upper Deck for 42391 TRF421X  [3404174]

Upper deck for TRF421X

This upper deck is offered as a direct spare part referenced by code 42391 for the TRF421X chassis family. It serves the upper mainplate position on the chassis and is intended for use as a replacement during repair or when changing chassis flex and balance as part of setup work.

The design is provided to match the original mounting layout used on the TRF421X platform, so it integrates with existing standoffs and fasteners without requiring modification. When replacing the upper deck, verify hole alignment and fastener lengths to maintain intended chassis geometry and avoid introducing unwanted binding or play.

As a hop-up or spare, the component's role is primarily structural and tuning-related: swapping deck pieces can slightly alter fore/aft flex characteristics, which may be used to fine-tune handling for different track surfaces. Keep an inventory of compatible screws and any original shims removed during the swap to preserve setup consistency.

Compatibility

Compatible with 42391 TRF421X as indicated by the part code and product listing.

Suitable for technicians and hobbyists who need a like-for-like replacement or who experiment with deck stiffness as part of chassis setup, the part fits into the TRF421X platform without chassis modification.