Futaba S3170G Outer Shell Replacement FUAS4158 (W/O PACKING)  [FUAS4158]

Overview of the Replacement Shell

The Futaba FUAS4158 is an outer case set produced for the S3170G servo and is supplied without retail packing. It is intended as a direct housing swap to protect the servo internals during bench maintenance and to replace damaged or weakened housings.

This component is designed around the S3170G model, so confirm the servo reference before purchase. The part replaces the casing only and does not alter electronics; it streamlines tasks such as bearing access, inspection, and component transfer during tuning sessions.

For installation, remove the horn and output gear where necessary, label and store shims and bearings, install internal parts into the new case, and secure screws with even pressure to avoid distorting the shell. Once reassembled, run the servo at a safe test voltage to check smooth movement and neutral positioning prior to refitting it to the model.

Replacing a worn case can restore consistent mounting points and alignment in the chassis, which helps achieve repeatable steering geometry and trimming during setup work.