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

6061-T6 Rear Piggy Back Shock Assembly

Purpose-built rear dampers for the TRAXXAS UNLIMITED DESERT RACER PRO-SCALE 4X4 using an L-shape piggy back and built-in piston spring to let you fine-tune rebound and improve high-speed load control.

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: fitted in place of the rear stock dampers, these units give increased shaft stiffness and an option for firmer coils to alter rebound and load handling. Use the top retainer and lower red screw for mechanical adjustments and confirm rear clearance and mount fitment before track testing.

Best used where a firmer rear and reduced flex are desired on the TRAXXAS UNLIMITED DESERT RACER PRO-SCALE 4X4; always check seals and oil level after installation and adjust rebound progressively to suit your course.