THRUST ANGLE
Thrust angle is the averaged direction the rear
wheels are pointing in relation to the vehicle’s center
line (Fig. 6). The presence of negative or positive
thrust angle causes the rear tires to track improperly
to the left or right of the front tires (dog tracking).
• Negative thrust angle means the rear tires are
tracking to the left of the front tires.
• Positive thrust angle means the rear tires are
tracking to the right of the front tires.
Improper tracking can cause undue tire wear, a
lead or pull and a crooked steering wheel. Excessive
thrust angle can usually be corrected by adjusting
the rear wheel toe so that each wheel has one-half of
the total toe measurement.
DIAGNOSIS AND TESTING - SUSPENSION AND STEERING
CONDITION POSSIBLE CAUSES CORRECTION
Front End Whine On Turns 1. Defective wheel bearing 1. Replace wheel bearing
2. Incorrect wheel alignment 2. Check and reset wheel alignment
3. Worn tires 3. Replace tires
Front End Growl Or
Grinding On Turns
1. Defective wheel bearing 1. Replace wheel bearing
2. Engine mount grounding 2. Check for motor mount hitting frame rail
and reposition engine as required
3. Worn or broken C/V joint 3. Replace C/V joint
4. Loose wheel lug nuts 4. Verify wheel lug nut torque
5. Incorrect wheel alignment 5. Check and reset wheel alignment
6. Worn tires 6. Replace tires
7. Front strut pin in upper strut mount 7. Replace the front strut upper mount and
bearing
Front End Clunk Or Snap
On Turns
1. Loose lug nuts 1. Verify wheel lug nut torque
2. Worn or broken C/V joint 2. Replace C/V joint
3. Worn or loose tie rod 3. Tighten or replace tie rod end
4. Worn or loose ball joint 4. Tighten or replace ball joint
5. Worn/loose control arm bushing 5. Replace control arm bushing
6. Loose stabilizer bar. 6. Tighten stabilizer bar to specified torque
Fig. 6 Thrust Angle
RS WHEEL ALIGNMENT 2-49
WHEEL ALIGNMENT (Continued)
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