[StillBored]

Sigh, this is not at all how most trucks/etc work.

The odometer is generally computed/measured at the output shaft of the transmission. The differential+tire size is then used to compute a mileage in the ECU (or old school via actual odometer gears feeding the odometer).

Its also why the discussion about adjusting ones odometer comes up frequently in offload communities where oversized tires, or differing gear ratios are run. Even outside of that, people (like myself) who run slightly oversized AT tires, even on the street have our odometers thrown off by a couple percent because the manufactures frequently don't provide a real number input to the ECU rather a selection of a few tire sizes. In my case, my truck has metric sized tires, which don't align perfectly with the preprogrammed LT sizes.

That is why there are various inline devices which can be plugged in to correct for nonstandard modifications (I believe this to be one of them http://hypertech-inc.com/SpeedometerCalibrator.aspx, from a random google search)

[_ea1k]

I didn't understand your reply until I realized that I had specifically mentioned the driveshaft. On those vehicles that you mention, it'd be much harder as you'd have to drop the transmission and connect to the crankshaft.

Not impossible, but probably not practical and certainly likely to void various parts of the warranty.