palbria

Hello, I am trying to help my son fix up his first truck. One of the things I am trying to do is replace the front 4x4 actuator, but the issue is that the old one won't unscrew. I am not sure if the previous owner put lock tight on the threads or what, but no matter what I do I can't get it to break free. I am guessing that I can't apply heat because of the actuator being mostly plastic, but I am out of ideas. Anyone have any thoughts? Thanks