When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
So a while back I went from a 3.08 rear to a 3.70 and the speed odometer was off by about 10 mph. I changer the drive gear inside the trans and got it closer. Now when the speed odometer read 60 mph my gps says 57 mph. I have a red driven gear which is 21 teeth is there anyone that can tell me what gear I can get to get it right on or closer if I can?
Thanks
Willcox has a chart in their help section. 3 MPH is not outside of any limits- I'd rather have the speedo read a little slow than fast. And FWIW: most all GPS units are accurate to within 10-20 feet anyway, so that could be some of your error. get on the highway with a stopwatch- 60 MPH mile marker to mile marker.