As DDW says it is a very simple device. There is an electric motor, cog type drive belt, planitary gears and an electric clutch. Check the gears for wear with a magnifying glass. You would probably find a bit a black dust in the housing either from the gears (they are plastic and run dry) or from the clutch. Ours has steered our 13 ton fin keel boat for over 20 years of summer sailing and cruising and shows no signs of wear.