On a 2003 if the rear end gears are changed to 3.55, obviously the tires would turn slower for a given speed. So at an actual 60mph the speedometer would indicate approximately 55mph.

How would this affect the shift points? Would the tranny shift sooner or later?

Are shift points RPM or MPH dependant or what determines them?


My guess is that since the speedometer reads lower than actual, the shift points will take place at higher actual speed and rpm's.

I had someone tell me the opposite. What makes sense?

TB

 

Changing gear ratio wouldn't make your tires turn slower to achieve the same speed. The difference in shift points would only be at a higher MPH. The RPMs the tranny shifted at probably wouldn't change, since the difference between 3.55 and 3.73axle ratio is not much. Don't know how much slower the speedo would read with 3.55s but it would be reading slow...Kevin