I don't show an electric actuator for your year truck. Are you installing GM parts, many cheaper units will fail prematurely, the over size tires shouldn't cause the actuator to fail. When you remove the actuator can you inspect inside the transfer case to see if something is causing the problem, I have seen where the engagement fork will break causing the actuator to fail, the transfer case will need to be disassembled and repaired to fix the problem.
Let us know what you find
Monday, May 25th, 2015 AT 9:43 AM