If you have decided to sell a junk truck for parts, you should know which will bring you the most cash and which are of no value at all. The most expensive parts are the bumper, doors, windows, mirrors, engine, transmission, rear end, and electronics. These parts are more often replaced than fixed in case of breakdown, so they are in high demand in the market for reused car components. You can also get good money for selling precious metal catalysts, a GPS system, and airbags that have not been used. And you will get much less cash for truck batteries, wiper arms, tires, wheels, and filters.