Yokomo SD-302DU Upper Center Transmission Case  [SD-302DU]

Upper center transmission case overview

This SD-302DU upper center transmission case from Yokomo is an RC-scale replacement upper housing intended for use with D-MAX standard parts. Its role is to secure the top half of the center transmission assembly, keep gear mesh consistent, and provide a stable mounting surface for shafts and bearings.

Installation is straightforward: remove the original upper case, transfer bearings and internal gears intact, then fit the SD-302DU and retighten fasteners while checking gear mesh and shaft alignment. Use the same bearing sizes and fastener routes as the original to avoid changing drivetrain geometry.

As a tuning item, the upper case affects drivetrain stiffness and access for maintenance. Using a rigid aluminium upper case can help preserve gear alignment under load and make repeatable adjustments easier during setup and trackside tuning. This part is described as an upper center case compatible with D-MAX standard parts and is intended for radio-controlled drivetrains only.