TRX-4 Rear Gearbox Mounts and Knuckle Arm Upgrade TRX4H100R by GPM  [TRX4H100R]

Rear knuckle and gearbox mount upgrade for TRX-4

This 54-piece aluminium upgrade is an aftermarket replacement kit for TRX-4 trail crawlers focused on the rear gearbox and knuckle arm assembly. The kit replaces rear gearbox mounts, inner and outer knuckle components, the rear axle joint and shaft, spindle gears and includes stainless fasteners so the factory interfaces remain compatible while mount geometry is adjusted.

Purpose and adjustments: the parts join the rear gearbox to the knuckles, stabilise internal alignment of gears and move the lower shock mounting points to allow small changes to damper angle and ride height. Adjustability is achieved by fitting the shock lower eyelet into the alternative holes provided on the knuckle and box mounts.

Build notes: main structural items are 6061 T6 aluminium with an open-style knuckle for easier assembly. When fitted the shock bodies sit marginally outboard compared with the stock vertical position, aiding chassis stability and permitting minor ride-height gains. Knuckle internals feature larger gear pitch and diameter and a lower axle centre that raises body clearance by about 1.2mm as described by the maker.

This kit suits builders wanting a lighter aluminium rear mounting solution to improve driveline stability and allow small tuning changes to shock geometry on TRX-4 crawlers; verify pendulum wheel clearance before installation.