Tamiya 9803571 3.0x4.0x2.7mm Spacer for TRF421X precision hop-up spacer  [9803571]

Precision 3.0×4.0×2.7mm spacer

This Tamiya 9803571 spacer is an RC-scale hop-up designed for precise spacing tasks on TRF421X-related assemblies. The part is listed alongside reference number 42391 and is intended to provide repeatable, small-step adjustments where tight tolerances matter, such as bearing seats, linkage pivots, and chassis mounting points.

Use the spacer when you need to correct axial play, set gear mesh clearance, or fine-tune suspension geometry without modifying major components. Its nominal dimension of 3.0x4.0x2.7mm makes it suitable for compact locations common on touring car chassis and detailed hop-up work.

Installation is straightforward: verify part orientation, slide the spacer onto the shaft or into the bore, and reassemble the affected sub-assembly. Work with care to avoid over-constraining bearings or introducing binding in rotating parts; a feeler check after assembly helps confirm free movement and correct preload.

For tuning, use this spacer as one of several incremental options to dial in handling characteristics. Small changes in spacer thickness or stack height can alter roll center, toe link geometry, and gear engagement, so record changes and test incrementally on the track to judge effects on cornering and drivetrain efficiency.