TRAXXAS UNLIMITED DESERT RACER PRO-SCALE 4X4 CNC-style Rear L-shape Piggy Back Dampers UDR139R/LN by GPM  [UDR139R/LN]

Aluminum 6061-T6 Rear Piggy Back Dampers

This is an RC-scale rear suspension hop-up designed for the TRAXXAS UNLIMITED DESERT RACER PRO-SCALE 4X4 platform. The unit uses an L-shape piggy back design with a built-in piston spring to allow tuning of rebound force and improve pressure load response during high-speed off-road runs.

Key engineering points retained from the original design:

• Spring coil: Main spring wire increased from 1.8mm to 2mm for firmer spring rate while the original spring remains compatible if a softer feel is preferred.
• Damper shaft: Shaft diameter increased from 3.5mm to 5mm to reduce bending under load and improve durability for RC off-road stresses.
• Body and sealing: Aluminum 6061-T6 shock body with a shock-absorb cap to provide a tighter seal aimed at reducing oil leakage risk.
• Adjustability: Built-in piston spring plus adjustable top spring retainer and the red screw on the bottom of the negative-pressure oil cylinder allow rebound and preload tuning to suit differing track and terrain setups.

Installation and tuning role: these dampers replace the rear units on the specified TRAXXAS chassis, offering a stiffer shaft and thicker coils to change rebound character and load handling. Adjustment is performed mechanically at the spring retainer and by the lower red screw to affect negative pressure and rebound damping; verify fit at the rear damper area before run testing.

Use these dampers when you need a firmer rear response and reduced shaft flex on the TRAXXAS UNLIMITED DESERT RACER PRO-SCALE 4X4; check seal torque and oil level after installation and adjust rebound incrementally to find the desired balance.