310S Steering and Suspension 1 — Questions and Answers
Question 1: What is the purpose of the caster angle in a vehicle's front wheel alignment?
- To control tire wear on the inner and outer edges
- To provide directional stability and steering wheel returnability (Correct answer)
- To distribute vehicle weight evenly across the tire tread
- To reduce rolling resistance for better fuel economy
Correct answer: To provide directional stability and steering wheel returnability
Caster is the forward or rearward tilt of the steering axis. Positive caster places the steering axis intersection point ahead of the tire contact patch, creating a trailing effect that promotes straight-line stability and helps the steering wheel return to centre.
Question 2: What symptom does excessive positive camber cause?
- Tire wear on the inside edge
- Tire wear on the outside edge of the tire (Correct answer)
- Vehicle pulling to the left
- Steering wheel vibration at highway speed
Correct answer: Tire wear on the outside edge of the tire
Positive camber tilts the top of the wheel outward from the vehicle. This concentrates the vehicle's weight on the outer portion of the tire, causing accelerated wear on the outside edge.
Question 3: What is the function of the stabilizer bar (sway bar) in a suspension system?
- To support the weight of the vehicle
- To resist body roll during cornering by transferring force between the left and right suspension (Correct answer)
- To absorb road shocks like a shock absorber
- To maintain proper ride height
Correct answer: To resist body roll during cornering by transferring force between the left and right suspension
The stabilizer bar is a torsion spring that connects the left and right suspension. During cornering, it resists the unequal suspension travel by transferring force from the compressed side to the extended side, reducing body roll.
Question 4: What causes a vehicle to pull to one side during braking?
- Unequal caster angles side to side
- Unequal braking force between the left and right sides due to a stuck caliper, contaminated pad, or hydraulic restriction (Correct answer)
- Worn stabilizer bar bushings
- Incorrect toe setting
Correct answer: Unequal braking force between the left and right sides due to a stuck caliper, contaminated pad, or hydraulic restriction
A pull during braking indicates unequal braking force. Common causes include a stuck or seized caliper, contaminated brake pads (oil/fluid on one side), a restricted brake hose, or worn pads on one side.
Question 5: What is the purpose of the toe alignment setting?
- To improve ride comfort over bumps
- To control the direction the tires point relative to the vehicle centreline, affecting tire wear and straight-line stability (Correct answer)
- To set the height of the vehicle
- To adjust the turning radius
Correct answer: To control the direction the tires point relative to the vehicle centreline, affecting tire wear and straight-line stability
Toe refers to whether the front edges of the tires point inward (toe-in) or outward (toe-out) relative to the vehicle centreline. Proper toe minimizes tire scrub and wear while maintaining directional stability.
Question 6: What does a dry park test evaluate in the steering system?
- Power steering fluid condition
- Worn steering and suspension components by rocking the steering wheel with the vehicle stationary and the wheels on the ground (Correct answer)
- Steering gear adjustment specifications
- Power steering pump pressure output
Correct answer: Worn steering and suspension components by rocking the steering wheel with the vehicle stationary and the wheels on the ground
A dry park test is performed with the vehicle on the ground and the engine running. A helper rocks the steering wheel while the technician visually inspects steering linkage components for looseness and wear.
310S Steering and Suspension 1
What is the purpose of the caster angle in a vehicle's front wheel alignment?