ARRMA ARA709068 Shim 12.2x21x1mm

The ARRMA ARA709068 Shim measures 12.2x21x1mm and is a genuine factory replacement shim for ARRMA vehicles.

Shims are thin precision washers used to control endplay and spacing on shafts, bearings, and gear assemblies throughout the drivetrain. At 1mm this is one of the thicker shims in the ARRMA range, used where a meaningful amount of spacing needs to be taken up in a single piece rather than stacked from thinner shims.

Correct shimming has an outsized effect on drivetrain life. The right clearance lets gears mesh at the proper depth and bearings sit square without side loading. Too much endplay allows shafts and gears to shuffle under load, producing noise, uneven tooth wear, and eventually stripped gears. Too little preloads the assembly into binding, which wastes power, builds heat, and shortens bearing life.

Shims are also among the easiest parts to lose during a rebuild. They stick to greased surfaces, drop out unnoticed when a gearbox is opened, and are simple to overlook during reassembly, which is exactly when a spare on the bench keeps the job moving.

This is a direct factory replacement that installs in the stock locations with no modification.