Will changing gear ratio change speedometer?
Will changing gear ratio change speedometer?
Speedometer and odometer are fed by a signal generator that counts axle revolutions. Just changing axle gears doesn’t affect it.
Does Regearing affect speedometer?
Due to the speedo sensor location the JK is reading the axle rotation as the JK rolls down the road so regearing doesn’t cause an issue with the speedometer because the speedo gear/sensor isn’t in the transmission and not affected by the increase in driveshaft revolutions.
How do you calculate the change in gear ratio?
Modifying the gear ratio is the equivalent of modifying the torque that is applied. The gear ratio is calculated by dividing the output speed by the input speed (i= Ws/ We) or by dividing the number of teeth of the driving gear by the number of teeth of the driven gear (i= Ze/ Zs).
Do bigger tires raise or lower gear ratio?
If the Tires Are Bigger, the Gears Should Be Lower. Going to lower gears (ironically, a numerically bigger ratio) will increase the rpms of an engine (taking for granted the same diameter tire and going the same speed).
What should the gear ratio be for a rear end speedometer?
Unless driven gears with more than 45 teeth, and/or drive gears with fewer than 15 teeth become available, it will be impossible to have an accurate speedometer with rearend gear ratios lower (higher numerically) than 3.75:1 – unless 27-inch or larger tires are installed.
What happens if you don’t change gears on speedometer?
If you didn’t change speedometer gears, actual vehicle speed would 73.1 percent of indicated speed (2.73/3.73 = .731). That being the case, what’s required is speedometer gearing that will result in the driven gear spinning at 73.1 percent of its current speed.
What kind of gearing does a 2.73 rear end need?
That being the case, what’s required is speedometer gearing that will result in the driven gear spinning at 73.1 percent of its current speed. The speedo gear combination for a 2.73 rear (assuming 26-inch diameter tires) is a 17-tooth drive gear and 37-tooth driven gear.
What should the drive ratio be for a 44 tooth gear?
Matching the 15-tooth drive speedometer gear up with a 44-tooth driven gear brings the drive ratio to 74 percent (15/17=.88; 37/44=.84; .88 x .84 = .739, which rounds to .74, or 74 percent). Still not quite enough. Will a 45-tooth driven gear do the job? Run the numbers through your calculator and you should come up with 72 percent.
Unless driven gears with more than 45 teeth, and/or drive gears with fewer than 15 teeth become available, it will be impossible to have an accurate speedometer with rearend gear ratios lower (higher numerically) than 3.75:1 – unless 27-inch or larger tires are installed.
Is there a way to correct the speedometer?
Depending on the vehicle manufacturer and the transmission type and manufacturer, there are speedometer gears available to correct the indicated speed. Check with your manufacturer’s parts supplier. We also have a calculator for speedometer correction after tire or wheel size changes.
If you didn’t change speedometer gears, actual vehicle speed would 73.1 percent of indicated speed (2.73/3.73 = .731). That being the case, what’s required is speedometer gearing that will result in the driven gear spinning at 73.1 percent of its current speed.
Where is the drive gear located on a TCI speedometer?
The accompanying charts show what gears were manufactured for each type transmission. TCI® now stocks the most popular speedometer gears. Note: Drive gear refers to the gear that is on the transmission output shaft. The driven gear is located in a removable housing usually in the tailhousing of the transmission.
