I posted this question once before and got no response. With all the interest Merle's question garnered, I thought I'd try again. My speedo doesn't work. I've disconnected it at the back and, with the truck moving, confirmed that the cable is good. When hooked up, the odometer works, but no speedo. The needle does jump around a little, though. I, too, have debated taking the speedo apart because of the grommets holding the housing together. As it now sounds like that may not be the issue I thought it was, my only question now is: what am I looking for once I get inside?