I replaced wheel speed sensors on front wheel hubs and output sensor on transmission.truck still showing 15mph faster than vehicle is actually going.seems to drop out of overdrive and rpms want to stay at 3000 after dropping out of od.took to shop,no codes.really stuck here.also replaced catalytic converter and shift solenoid s.2000 Chevrolet c/k2500 pick up 2 wheel drive
Often when people put larger tires, they swap crown gears too.
Check the door sticker RPO codes for gear ratio, and compare to what's actually in the axle.
Might sound stupid...but how do I check the sizes of the gears in the actual axel?
You're not interested in size. Axle ratio is the number of time the driveshaft has to turn to give one rotation of the wheel, and it's given by the ratio of the number of teeth in the pinion gear to the number of teeth in the crown gear.
there's a few ways to check:
1) if legible, check the code stamped into the axle tube
2) open it up and read the stamp on the crown gear
3) turn the wheel by hand and count the driveshaft rotations
Ok thanks
wheel speed sensors are for ABS only
Speed sensor for transmission and speedometer is on the transmission tail housing.
Do you have OEM size tires? OEM axle?
MMJoe is on the right track. Are the tires OEM diameter? Oversized, or undersized will change the speedo reading.
When I bought it, the tires on it were 2 sizes too big,so I replaced them with tires that are factory size.still had the same problem,so I replaced the abs speed sensors and the transmission speed sensor.still having same problem.shop told me replacing the tires and speed sensors, would fix it.kind of at a loss.not getting any codes either
When I bought it, the tires on it were 2 sizes too big,so I replaced them with tires that are factory size.still had the same problem,so I replaced the abs speed sensors and the transmission speed sensor.still having same problem.shop told me replacing the tires and speed sensors, would fix it.kind of at a loss.not getting any codes either