Lead/pull is the deviation of the vehicle from a straight path on a level road with no pressure on the steering wheel. Lead is usually caused by the following conditions:
| • | Poor tire construction |
| • | Uneven brake assemblies |
| • | Improper tire and wheel alignment in the front tires (rear tires will not cause lead) |
Tire construction can be a cause of 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, and the tire will tend to roll like a cone.
Use the lead/pull correction table in order to verify that improper tire and wheel alignment is not mistaken for tire lead.
Step | Action | Value | Yes | No | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Inspect the tire/wheel assemblies for the following:
Do any of the above conditions apply? | -- | ||||||||||||
2 | Repair/replace the tire/wheel assemblies as necessary. Is the repair complete? | -- | -- | |||||||||||
3 | Inspect the front/rear suspensions for the following:
Do any of the above conditions apply? | -- | ||||||||||||
4 |
Is the repair complete? | -- | -- | |||||||||||
5 | Inspect the power steering gear and pump for the following:
Do any of the above conditions apply? | -- | ||||||||||||
6 | Repair/replace components as necessary. Is the repair complete? | -- | -- | |||||||||||
7 |
Does the vehicle still lead/pull? | -- | System OK | |||||||||||
8 | Does the vehicle lead/pull in the opposite direction? | -- | ||||||||||||
9 |
Does the vehicle still lead/pull? | -- | ||||||||||||
10 |
Does the vehicle still lead/pull? | -- | ||||||||||||
11 | Replace the left rear tire. Is the repair complete? | -- | System OK | -- | ||||||||||
12 | Replace the left rear tire. Is the repair complete? | -- | System OK | -- | ||||||||||
13 | Verify proper system operation. Does the original condition still exist? | -- | Verify the customer complaint. Begin the diagnosis again. Go to Step 1 | System OK |
