could somebody explain gear ratios to me? now I understand that one of the two parts of the ratio is tire revolutions and the second is drive shaft revolutions, but which is which. ie with 3.42 gears is it the tires turning 3.42 times or is it the driveshaft turning 3.42 times?
I figure it'll be the driveshaft cause they make different diameter tires. The reading would be inconsistant with the tire depending on the size tires you put on, where the driveshaft will always be the same. It's just my guess.
Yep, its the driveshaft. With 3.42 gears, the driveshaft turns 3.42 times for every 1 time the rear axle turns.
Another thing to look at is the tire circumfurance. The taller tire you have the bigger the circumfurance. The axle turning over one time on a taller tire is going to travel further than a shorter tire.
Exactly... Thusly, when you put a taller tire on, you effectively raise the gear ratio, i.e. a lower number ratio. If you install a deeper (numerically higher number) gear ratio and do not change the speedo gear, your speedometer and odometer will register faster than you are actually running. When I installed the 4.56's into my Suburban instead of the 3.73's, 60 mph on the clock was actually nearer to 47 mph. Incidentally, even with the OD, at interstate speeds, it pulled around 4800 rpm:shock: ran it up and down the interstate like that with no problems except for the 8 mpg. Worse mileage in town, but fun out of the hole!!:Brow: :Brow:
