I have never torn into or rebuilt a veederoot. I do not need them to totally work because my pumps are not working pumps any longer. I clean them up and lube them to where they turn and reset. I have one I cleaned up , it turns free and easily. I hooked a drill to the yoke on the underside, it calculates fine, When it's turned and reset, everything goes to zero except one set of gallon wheels. They reset to 77 0/10. Am I going to have to take the veederoot apart , or is there a simple way to get those wheels back in sync? Thanks , Mike.