My speedometer is not accurate. It hasn't been for a while. My guess is that it's about 5-10 MPH below the true speed. Any ideas how to fix? I don't know if this matters but the transmission was rebuilt in '97.
the speed-o in my 72 is WAAAAAYYYYYYY off. Like 20-40 MPH. The other day on the highway, I was keeping with the flow (about 60-65) and my speed-o was reading 100+ tach about 4 grand.
Somewhere in it's life a PO changed from the stock rear and threw in 4:11s, and changed the tire size. I have a replacement center section with 3:50s to put in and will be replacing the tires in the spring. Then hopefully the speed-o willbe a lot closer. In the mean time I use the tach to guess-ti-mate my speed.
My speedometer is not accurate. It hasn't been for a while. My guess is that it's about 5-10 MPH below the true speed. Any ideas how to fix? I don't know if this matters but the transmission was rebuilt in '97.
Thanks,Tom.
Check the "sticky" about "speedometer gear information" posted by Soaring. It's located at the top of the threads.
What you can do is pull the cable from the trans and see what color it is. Go to a Ford dealer and tell them the color of the gear you have and how much the speedo is off. They can get you the closest gear possible to get your spedo accurate again.
Printable Version
'66: Speedometer not accurate... - 
