Radial Tire Lead / Pull Description

Radial Tire Lead / Pull Description
"Lead / Pull" 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.
- Improper tire and wheel alignment.
- Uneven brake assemblies.
- 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.