What Gear Do I Need?

SPEEDOMETER GEARING ADAPTERS come in many shapes (Straight, Offset, Right Angle and Dual Drive). Applications for Light Duty vehicles, American and Japanese, as well as Heavy Duty OTR and Industrial Vehicles. If you want the correct OEM replacement or if you need to install one to correct for tire size, axle ratio or transmission change we are your source. They are designed to screw directly to the Transmission, if for some reason that is not possible, we can modify your Cable and Housing or build you a new one, so the Adapter will fit Inline.

See our WHAT GEAR DO I NEED? page to help determine what you need. Or just give us a call and we can walk you through it.

There are 250 different ratios available (see chart), so getting what you need is as easy as a phone call or sending an email.

CHANGING DRIVEN GEAR?

INDICATED SPEED X NUMBER OF TEETH ON GEAR / ACTUAL SPEED

= NEW DRIVEN GEAR

CHANGING DRIVE GEAR?

ACTUAL SPEED X NUMBER OF TEETH ON GEAR / INDICATED SPEED

= NEW DRIVE GEAR

NO CURRENT DRIVEN GEAR?

NUMBER OF TEETH ON DRIVE GEAR X AXLE RATIO X TIRE REV/MILE / 1000

= DRIVEN GEAR

NO CURRENT DRIVE GEAR?

NUMBER OF TEETH ON DRIVEN GEAR X 1000 / AXLE RATIO X TIRE REV/MILE

= DRIVE GEAR NEEDED

NEED A CORRECTING ADAPTER?

TIRE DIAMETER X .05 X TEETH ON DRIVEN GEAR/ AXLE RATIO X TEETH ON DRIVE GEAR

= ADAPTER RATIO

CALCULATING TIRE REV/MILE

63360” PER MILE

TIRE DIAMETER X 3.1416 = CIRCUMFERENCE

63360” PER MILE/CIRCUMFERENCE

= TIRE REV/MILE

CALCULATING SENSOR PULSES PER MILE

TIRE REV/MILE X SENSOR GEAR TEETH OR SENSOR PULSES X AXLE RATIO = PULSES PER MILE

EXAMPLE FOR NEEDING A NEW DRIVEN GEAR

50MPH INDICATED SPEED X 20 TEETH/55 ACTUAL SPEED

= NEED AN 18 TOOTH GEAR