Yokomo BM-504 Drive Gear w/Header Card — Drive gear for B-MAX4 input shaft  [BM-504]

Drive gear for B-MAX4

The Yokomo BM-504 Drive Gear w/Header Card is a standard replacement drive gear intended for the input shaft on B-MAX4 chassis standard parts. This is an RC-scale accessory supplied as a pair to support straightforward part swaps during routine maintenance or minor repairs.

Functionally the part sits on the input shaft and transmits motion through the gearbox train; it is supplied with a header card for inventory and identification. Installation is mechanical and requires basic disassembly of the transmission area to remove the original gear and press or slide the new gear onto the input shaft, taking care to preserve alignment and any spacing shims from the original assembly.

In tuning or repair contexts this component is used when replacing worn teeth or keeping a matched set of spare drive gears on hand. It is suited to hobbyists who perform periodic gearbox checks, quick part swaps trackside, or systematic maintenance at the bench.