Futaba S9155/S9255/S9351 First Gear Replacement - FU1K18802  [FU1K18802]

First Gear for Futaba S9155, S9255 and S9351 Servos

This is a replacement first gear designed specifically for Futaba servo models S9155, S9255, and S9351. Supplied as a single gear, it is intended for rebuilds when the original first gear shows wear, stripped teeth, or impact damage.

Role and tuning impact: the first gear meshes the motor pinion with the remainder of the gear train, so a worn first gear can cause slop, uneven centring, and reduced positional accuracy. Installing a fresh first gear restores proper tooth engagement and helps maintain repeatable servo centring during setup and tuning.

Installation notes: confirm compatibility with S9155, S9255, and S9351 before disassembly. Remove the servo horn and case carefully, inspect splines and the mating pinion for wear, align splines correctly when reassembling, and verify free rotation before powering the servo. Use appropriate small hand tools and avoid over-tightening fasteners that could bind the train.