It's a bit time consuming to explain the full procedure, but hidden under the coil spring is a tiny circlip which must be removed so the odo wheels can be slid to the left andd then set on "zero" starting with the RH wheel and then "zeroing" each wheel to the left of the farthest right hand wheel. CRITICAL TO EXACTLY ALIGN THE WHEELS. THEY CAN LOOK ALIGNED AND READ OUT CROOKED WITH JUST A COUPLE MILES ON THEM. IF YOU'VE NEVER DONE THIS PROCEDURE BEFORE, AFTER ALIGNING WHEELS, BEST TO DO A TEST RUN ABOVE 10 MILES, TO MAKE SURE WHEELS ALIGN PERFECTLY.
If odo is not a "K0" type, WILL NOT HAVE FOREMENTIONED CIRCLIP !!!!