Replacement Outer Case for S3170G Servo - Futaba FUAS4158 (Without Retail Pack)  [FUAS4158]

Product Summary and Fitment

The Futaba FUAS4158 case set is an outer casing designed for use with the S3170G servo and is supplied without retail packaging. It serves as a direct shell replacement to protect and house the internal components during maintenance and to replace damaged housings.

Compatibility is centred on the S3170G; confirm your servo model before fitting. This component is a physical case swap only and is not an electrical or performance upgrade. It supports workshop activities like bearing access, component inspection, and systematic reassembly during tuning work.

For installation, remove the servo horn and output gear as needed, note the order of shims and bearings, transfer internals into the new case, and secure screws with care to avoid distorting the shell. After reassembly, bench-test the servo at a safe supply to check for smooth travel and correct neutral position before refitting in the model.

Replacing a worn case can reinstate accurate mounting geometry and alignment, which assists with repeatable setup adjustments and steering trim consistency during track or field tuning.