The Yokomo BM-503 is a direct replacement diff ring gear intended for use in B-MAX4 RC differential assemblies. This item is supplied as two ring gears and is designed for scale model differential rebuilds and routine maintenance rather than any real vehicle application.
When repairing or refreshing a B-MAX4 differential, matching the ring gear tooth count and fit is important for consistent mesh and predictable handling. The BM-503 units are suitable where the stock ring gear requires replacement during rebuilds or when preparing a diff for tuning work.
Installation notes: confirm the ring gear seats flush on the differential case, check pinion-to-ring gear mesh with a shim method appropriate for your spur and pinion setup, and test spin smoothness before final assembly. Use compatible bearings and hardware from the B-MAX4 parts list to avoid fitment issues.
Copyright © 2008-2026 rcjaz.com All rights reserved