Save the cost of a new servo, just replace worn or damaged gears with
All gears are white nylon construction.
One first gear (not available in a different gear set)
One second gear (available in FUTM3410, 3411, or 3390)
One third gear (available in FUTM3410, 3411, or 3390)
One metal final gear
Disassembly and reassembly of the servo.
For the S34G and S134G gear set, use FUTM3390.
This will fit in the S3302 and S3801 servos, but does not include
metal gear or bearing so servo could fail under high torque