TAMIYA TB-04 Rear Arm Bulk Aluminium TB4009 by GPM  [TB4009]

Billet aluminium rear bulk for TB-04

This aluminium rear arm bulk replaces the stock plastic unit on the TAMIYA TB-04 chassis and is offered as a single set for direct upgrade. The part gives a more rigid mounting point for rear arms and associated suspension links, helping reduce flex under load.

Fitting is straightforward for those familiar with basic RC maintenance: remove the factory rear bulk, move over sealed bearings and any link hardware, then secure the aluminium bulk using the original mounting locations. A hex driver and attention to fastener torque are usually all that is required to avoid introducing chassis distortion.

From a setup perspective the TB4009 part increases the consistency of rear geometry and smooths suspension adjustments. Expect subtle shifts in handling as the rear becomes stiffer; adjust shock rates and anti-roll settings incrementally while testing to find the best balance between turn-in and traction.