Stihl Drive Gearbox Wear or Damage

Robot lawnmower produces a high-pitched whining or grinding noise from one wheel.

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Possible Causes

Worn gears in drive gearbox, Lack of lubrication (sealed unit failure), Debris inside wheel hub, Bent motor shaft

How to Fix / Troubleshooting

Safety first: Turn the mower OFF before handling wheels.

Identify side: Gently push the mower and listen to determine which wheel is noisy.
Check for debris: Remove the wheel (if user-removable per manual) and clean any dirt or stones from the hub area.
Spin wheel and shaft: Rotate the motor shaft by hand. Roughness or grinding indicates internal gearbox damage.

Drive gearboxes in Stihl iMOW units are typically replaced as a complete motor/gearbox assembly. Have the noisy side replaced by an authorized service center.

Repair Difficulty

Hard 4/5

Required Part

Drive Motor and Gearbox Assembly

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