How much for speedometer recalibration

Changing the stock parts, including the vehicle's tires, can throw off the speedometer calibration; larger tires cause the speedometer to read a speed slower than the vehicle's actual speed while smaller tires cause the speedometer to read a speed faster than the vehicle's actual speed.

You may recalibrate a speedometer in a few simple steps. Open the vehicle's hood and locate the transmission. Unscrew the speedometer cable from the transmission's tail shaft and use a crescent wrench to unscrew the bolt holding the gear housing cover in place.

Remove the plate to expose the two gears: the drive gear mounted inside of the transmission and the driven gear attached to the speedometer cable. Count the number of teeth on the drive gear and note the number. Measure from the top of one of the vehicle's wheels to the center of the wheel.

Multiply this number by two to determine the diameter of the tire. Divide 20, by the tire's diameter to determine the tire's revolutions per mile. A Fairfax reckless driving attorney will be able to explain if your case is one in which the speedometer calibration could make a positive difference.

An attorney with experience can help someone determine if a speedometer calibration would be valuable for your defense. Virginia Reckless Driving Lawyer. In fact, most manufacturers build speedometers so they fall within a fairly narrow tolerance range, no more than 1 percent to 5 percent too slow or too fast. As long as a car is maintained at factory specs, its speedometer should continue to register vehicle speed within this range. But, if a car is modified, its speedometer may need to be recalibrated.

Changing tire size is one of the most common things car owners do that can affect speedometer accuracy. Consider the example below. Your car comes with factory-installed tires that are That means the circumference of each tire is Each new tire has a circumference of This has a tremendous affect on your speedometer, which will now indicate a speed that is too slow by almost 13 percent.

Now, some people choose to purchase a brand new instrument cluster at the dealership when they think even something little is off with their speedometer. Of course, that comes with quite a large price tag. Those prices do not even include taxes and fees.

However, that is certainly not necessary.