Radial Tire Lead Description
“Lead” is the deviation of the vehicle from a straight path on a level road even with no pressure on the steering wheel.
Lead is usually caused by the following conditions.
Incorrect alignment.
Uneven brake adjustment.
Tire construction.
The way in which a tire is built can produce lead in a vehicle. An example of this is placement of the belt. Off center belts on radial tires can cause the tire to develop a side force while rolling straight down the road. If one side of the tire has a little larger diameter than the other, the tire will tend to roll to one side. This will develop a side force which can produce vehicle lead.
The procedure in the figure (Lead Diagnosis) should be used to make sure that wheel alignment is not mistaken for tire lead.
Part of the lead diagnosis procedure is different from the proper tire rotation pattern currently in the owner and service manuals. If a medium to high mileage tire is moved to the other side of the vehicle, be sure to check that ride roughness has not developed
Rear tires will not cause lead.