DFFT Steering and Suspension 1 — Questions and Answers
Question 1: A vehicle wanders excessively on the highway and requires constant steering corrections. What is the most likely cause?
- Worn tie rod ends causing excessive play in the steering (Correct answer)
- Low tire pressure on the rear axle
- A seized rear sway bar link
- Incorrect camber angle on the front wheels
Correct answer: Worn tie rod ends causing excessive play in the steering
Worn tie rod ends create looseness in the steering linkage, allowing the front wheels to wander rather than tracking in a straight line.
Question 2: A vehicle pulls to the left when the driver releases the steering wheel. What is the most likely alignment fault?
- More positive camber on the right front wheel than the left (Correct answer)
- Excessive toe-in on both front wheels
- Insufficient caster angle on the steering axis
- Worn rear shock absorbers
Correct answer: More positive camber on the right front wheel than the left
A vehicle with unequal camber will pull toward the side with the most positive camber because that wheel generates more lateral force.
Question 3: A customer reports a clunking noise from the front suspension when driving over bumps. What should be inspected first?
- Sway bar end links and bushings (Correct answer)
- Tire tread depth and condition
- Power steering fluid level
- Wheel bearing play and condition
Correct answer: Sway bar end links and bushings
Sway bar end links and bushings are common sources of clunking over bumps because they connect the sway bar to the suspension and can wear or loosen over time.
Question 4: Excessive tire wear on the outer edges of both front tires is present. What alignment angle is most likely out of specification?
- Excessive negative camber on both front wheels
- Excessive toe-in on the front axle
- Insufficient caster on the steering axis
- Excessive positive camber on both front wheels (Correct answer)
Correct answer: Excessive positive camber on both front wheels
Excessive positive camber tilts the top of the tire outward, putting more load on the outer tread edge and causing it to wear faster than the inner edge.
Question 5: What is the purpose of the caster angle in a vehicle's front suspension alignment?
- To provide steering returnability and straight-line stability (Correct answer)
- To prevent tire edge wear by keeping the tire perpendicular to the road
- To equalize the load between inner and outer wheel bearings
- To control the turning radius during cornering
Correct answer: To provide steering returnability and straight-line stability
Caster creates a mechanical trail that causes the front wheels to self-center after a turn and resist deflection from road imperfections, promoting straight-line stability.
Question 6: A vehicle has a steering wheel that vibrates at highway speed but is smooth at low speed. What is the most likely cause?
- A front wheel that is out of balance (Correct answer)
- Worn front strut mounts
- Loose power steering rack mounting bolts
- Incorrect front toe alignment setting
Correct answer: A front wheel that is out of balance
Wheel imbalance creates a centrifugal force that increases with speed, typically causing steering wheel vibration at a specific speed range.
DFFT Steering and Suspension 1
A vehicle wanders excessively on the highway and requires constant steering corrections.
What is the most likely cause?