Robot lawnmower makes loud clicking or knocking noises from the drive wheels while moving.

Safety first: Turn OFF the mower and remove it from the lawn before inspecting the wheels.

• Check wheel attachment: Ensure the drive wheels are firmly attached to the axles. Tighten any retaining nuts or clips.
• Inspect for debris: Remove the wheels if possible and clean out any stones or hard debris from the hub and gearbox area.
• Listen while rotating: Manually rotate each wheel and listen for clicking or grinding. If present, the internal gearbox is likely damaged.
• Replace gearbox: Replace the affected drive motor/gearbox assembly with an Einhell‑compatible part. This usually involves opening the housing and disconnecting the motor wiring.