My speedometer never worked, after I was done rebuilding my 58'1/2 ton the speedometer just screeched and bounced around wildly so I took the speedometer out. The ODOMETER worked fine. Because of a bad syncro in the original transmission I found a replacement from a 59. After the switch my odometer never worked. The cable hooks up the same. I even switched the speedometer gear on the side of the transmission. They looked identical but it didn't help. I assume the gear on the mainshaft of the transmission is out. any other ideas? should I rebuild the original transmission with the bad synchro or the working transmission which doesn,t turn my odometer(speedo cable)?