Review on Dorman 600 500 4 Wheel Drive Switch by Jordan Ford

This was EXACTLY the part I needed - the old vacuum switch allowed a partial vacuum leak into the line leading to the hub lock actuator diaphragm mechanism, causing "gear drag" from the front axle when the Hubs also attempted partial engagement in 2-wheel drive mode. Replacing this switch ensured that the vacuum was only delivered when it was needed. The old one was stuck with the ball plunger partially depressed so the old one was leaking. An installation tip: this part will tilt forward just a SMALL bit when properly oriented to screw into the hole in the top of the transfer case. It does NOT fit perfectly vertically. Otherwise, you can spend hours trying! Also make sure the small pin on the switch aligns with the indentation on the triple wire to avoid tangling the wires. Otherwise it will NOT work properly!