Futaba FUAS3274 Replacement Gear Set for S3117 S3157 Servos  [FUAS3274]

Service replacement for S3117 and S3157 internal gears

This gear set is an RC-scale replacement pack intended for Futaba-listed servo models S3117 and S3157 and the related internal gear assemblies identified by AS3274 and EBS3358 codes. It is focused on restoring correct internal gear geometry and engagement after wear, helping to keep servo performance consistent in modelling applications.

Apply this set when a servo exhibits excessive backlash, poor centring or intermittent gear noise from worn or damaged teeth. The kit is supplied to mirror the original gear train arrangement described by the product identifiers.

Installation notes and tuning role:

• Confirm the servo case markings indicate S3117 or S3157 before dismantling the unit.
• Remove the cover and compare the existing gear stack with the replacement set to confirm correct orientation and order.
• Once installed, rotate the output spline by hand to verify smooth movement and correct mesh before reapplying power or connecting linkages.
• Perform transmitter centring, trim and endpoint checks to ensure restored travel; listen for any unusual noises while testing under low load.