TRAXXAS TRX4 Trail Crawler Stainless Steel Open Shim 5.2x8.0x1.3 4pcs by GPM TRX4010/OPSH  [TRX4010/OPSH]

Open shim for TRX4 driveline tuning

This is an RC-scale stainless steel open shim designed for fine stack and spacing adjustments on Traxxas TRX4 components that use the TRX4010 interface. The open (C-shaped) profile lets you slip the shim over shafts or pinion areas without fully disassembling assemblies, so small clearance changes can be tested quickly.

Use this shim to correct minor axial play, set precise bearing preload, or adjust gearbox and axle stack height in trail crawling setups. Because it’s steel, the shim holds thickness and flatness under load better than softer materials, making incremental tuning repeatable.

Installation is straightforward: clean mating surfaces, slide the open shim into position, verify fit and rotational clearance, then cycle the drivetrain slowly to check for binding before full operation. Keep shims paired and document positions when testing different stack configurations.