GM Service Manual Online
For 1990-2009 cars only

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:

    • Off center belt
    • 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.

Lead/Pull Correction Table

Step

Action

Value(s)

Yes

No

1

Inspect and repair/replace tire/wheel assemblies for:

    • Correct tire pressure
    • Excessive/uneven tire wear
    • Correct tire size
    • Excessive radial/lateral wheel runout
    • Out of balance

Is action complete?

--

Go to Step 2

--

2

Inspect and repair front and rear suspensions for:

    • Damage
    • Excessive wear
    • Loose Components
    • Excessive wheel bearing play

Is action complete?

--

Go to Step 3

--

3

Inspect and repair power steering gear and pump for:

    • Damage
    • Excessive wear
    • Variable Effort steering for DTCs

Is action complete?

--

Go to Step 4

--

4

  1. Cross-switch front tire/wheel assemblies.
  2. Road test vehicle.

Does vehicle still lead/pull?

--

Go to Step 5

System OK

5

Does the vehicle lead/pull in the opposite direction?

--

Go to Step 6

Go to Wheel Alignment Measurement

6

  1. Cross-switch left front tire/wheel assembly with left rear tire/wheel assembly.
  2. Road test the vehicle.

Does vehicle still lead/pull?

--

Go to Step 7

Go to Step 8

7

  1. Cross-switch right front tire/wheel assembly with right rear tire/wheel assembly.
  2. Road test the vehicle.

Does vehicle still lead/pull?

--

Go to Wheel Alignment Measurement

Go to Step 9

8

Replace left rear tire.

Is repair complete?

--

System OK

--

9

Replace right rear tire.

Is repair complete?

--

System OK

--