Earlier this year I removed and disassembled the instrument panel when I replaced the wiring harness. I made some modifications to the speedometer panel so I could replace the clock with a mini tach, removed the idiot lights/fuel gauge and in their place added an aftermarket mini fuel gage. Since I cut through the circuit panel I had to install bulbs with sockets for the signal indicators and dash lights. Everything works fine but the speedometer is now off by 7 mph at all speeds. I verified this with a GPS. Prior to me messing with the dash the speedo was pretty much right on (verified with a GPS). Evidently all the commotion with the instrument panel mods threw the speedo calibration out of whack. How can I get it back in sync?
I know it is mechanical but there must be springs or something in the housing where the cable connects that needs to be calibrated. Just wondering if it can be done at home or I need to search near and far for a speedometer shop.