So I got a Warn M8000 on an ARB bumper with one of my recent trucks. Probably at least 10 years old. Winch quit working so I removed it and took it apart. Brushes were completely corroded in place, no visible effort on the manufacturer's part to waterproof the brush holder section. Truck came out of NOVA area, so not even particularly highly corrosive environment. As a mechanical engineer working in industry for 35 years I consider this pretty poor design for a product that is known to be basically continually exposed to the elements. If you have one you might want to put it on your maintenance list to either remove, clean, and silicone seal or at a minimum remove a screw or two and spray the internals with an anti-corrosive spray.