SpeedometerGears
This is for the cable driven speedometers, for DRAC/VSSB see farther down the page
2WD - 700R4 Cable Driven Speedometer Gears
Drive Gear Color
Driven Gear - Color
With 15 Tooth Drive Gear
With 17 Tooth Drive Gear
With 18 Tooth Drive Gear
DRAC/VSSB Adjustment/Calibration
The DRAC and VSSB speedometer adjustment is extremely similar but the VSSB has a redundant set of pins.
For more info, see this page, and the attached PDF on this page: http://www.msgpio.com/manuals/mshift/drac.html
With the pins at the bottom of the module the setup is as follows:
DRAC = Pin numbers ascend from the left to the right in order 1-2-3-4-5-6-7
VSSB = First 7 pin numbers descend from the left to the right 7-6-5-4-3-2-1, and the next set of pin numbers ascend from left to right 1-2-3-4-5-6-7 creating a redundant mirror of pins.
To calculate the input ratio you can use this handy calculator http://tbichips.com/?page_id=504 or use the following formula to get the closest Input-Ratio for setting your pins:
Input-Ratio = inches per mile x gear-ratio x number of pulses per revolution from sensor ÷ by the tire circumference in inches x pulses per mile output to RWAL module
Input-Ratio = 63360 x gear ratio x 40 ÷ tire circumference x 128000
Find your gear ratio on the differentials page, and your stock tire circumference on the tires page.