ASE Practice Test (A4: Suspension & Steering) 2 — Questions and Answers
Question 1: A vehicle pulls to the left during hard braking but tracks straight during normal driving. What is the MOST likely cause?
- Incorrect front wheel alignment — excessive caster difference side to side
- A seized or sticking brake caliper on the right front wheel (Correct answer)
- Worn left front strut causing nose dive during braking
- Excessive positive camber on the left front wheel
Correct answer: A seized or sticking brake caliper on the right front wheel
A brake pull (pulling only during braking) is classically caused by a sticking caliper. If the right front caliper sticks and applies less braking force than the left, more braking force acts on the left side, pulling the vehicle to the left. This only manifests during braking, not during normal driving.
Brake pull occurs when one front brake applies more or less force than the opposite side, creating a net lateral force on the vehicle. Vehicles pull toward the side with greater braking force. A pull to the left during braking indicates the left front brake is applying more force, or the right front brake is applying less force. A seized or sticking right front caliper slides on its mounting pins but does not apply braking force effectively. The pads may not fully contact the rotor, or may contact intermittently. This asymmetric braking — strong left, weak right — pulls the vehicle to the left. Alignment factors such as caster can cause steering pull during normal driving (a vehicle with more positive caster on one side tends to pull toward the side with less caster), but caster-induced pull occurs constantly, not just during braking. The question specifies the pull only occurs during hard braking — this identifies it as a braking system issue. Other causes of brake pull include: unequal tire pressures, worn brake pads on one side only, a collapsed brake hose that restricts fluid return (causing a dragging caliper), oil or fluid contamination on one brake pad, and incorrect pad material mixing (different friction coefficients side to side).
Question 2: A customer reports that the steering wheel is off-center (turned slightly to the right when driving straight). The vehicle tracks straight and there is no pull. What is the MOST likely cause?
- Unequal toe settings on the front wheels (Correct answer)
- Incorrect caster setting on one front wheel
- The steering wheel was installed in the incorrect position on the column shaft
- Unequal camber settings causing a pull the driver is correcting
Correct answer: Unequal toe settings on the front wheels
An off-center steering wheel with no pull indicates that individual toe angles are not equal, even though total toe may be correct. If the right wheel is toed out more than the left (or left more in), the steering rack and tie rods sit in a position that places the wheel off-center.
Toe is the inward or outward angle of the front wheels when viewed from above. Total toe (sum of both sides) affects tire wear and straight-line stability, but the individual toe setting on each side determines the centered position of the steering system. The steering rack and tie rods act as a mechanical linkage between the two front wheels. When total toe is correct but the individual toe angles are unequal (for example, right wheel has 0.1° toe-in and left wheel has 0.3° toe-in for a total of 0.4° toe-in), the rack and tie rods must be positioned off-center to achieve this asymmetry. This off-center rack position rotates the steering wheel from its centered position. The vehicle tracks straight (no pull) because total toe is correct and no lateral force is generated. The driver simply notices the wheel isn't centered. The fix is to adjust individual tie rod lengths to equalize the toe angle on each side while maintaining the correct total toe specification. Most alignment machines display individual wheel toe and will indicate when the steering wheel is centered. An incorrectly positioned steering wheel on the column shaft is another possible cause, but this is typically a service error, not a common occurrence.
Question 3: When performing a wheel alignment, a technician finds the rear camber is -1.5° on both sides, and the rear toe is 0.0° on both sides. The specification is -0.5° to -1.0° camber and 0.1° to 0.3° toe-in. Which tire wear pattern would result from the out-of-spec camber?
- Even wear across the tread
- Wear on the inside edge of the rear tires (Correct answer)
- Wear on the outside edge of the rear tires
- Cupping or scalloping across the tread
Correct answer: Wear on the inside edge of the rear tires
Excessive negative camber (-1.5° when spec is -0.5° to -1.0°) means the tops of the tires tilt inward too much. This places more weight and contact pressure on the inner portion of the tire tread, causing accelerated wear on the inside edge of the rear tires.
Camber is the inward or outward tilt of the wheel when viewed from the front. Zero camber means the wheel is perfectly vertical. Negative camber means the top of the wheel tilts toward the vehicle centerline. Positive camber means the top tilts away from the vehicle. The camber angle determines how load is distributed across the tire contact patch. At zero camber with a properly inflated tire, load distributes evenly across the tread width. With negative camber, the inside portion of the tread is pressed more firmly against the road surface than the outside portion. At -1.5° (outside the -0.5° to -1.0° specification), the inside edge of the rear tire carries disproportionate load. This accelerates wear on the inner shoulder and inside tread blocks while the outer portion wears normally. The result is a tire that wears down to the wear indicators on the inside while still having significant tread depth on the outside — often causing premature tire replacement. Excessive positive camber would cause opposite (outside edge) wear. Zero toe or toe-out causes feathering (saw-tooth wear pattern viewed from the side) and outer edge wear on each tire. Cupping or scalloping indicates a shock absorber or strut that is allowing the tire to bounce and hop against the road surface.
Question 4: A technician is performing a steering system inspection and finds excessive play in the steering wheel (more than 2 inches before the wheels respond). The steering is rack and pinion type. Where should the technician look FIRST?
- Inner tie rod ends (ball joints on the rack) (Correct answer)
- Outer tie rod ends
- Rack and pinion mounting bushings
- Steering column U-joint
Correct answer: Inner tie rod ends (ball joints on the rack)
On a rack-and-pinion steering system, inner tie rod ends (rack end ball joints) are the most common source of excessive play. These joints connect the rack to the tie rod shafts and wear allows the tie rod to move relative to the rack, contributing directly to steering wheel free play.
Excessive steering wheel free play means there is mechanical looseness somewhere between the steering wheel and the tire contact patch. On a rack-and-pinion system, the path includes: steering wheel → column → U-joints → pinion gear → rack → inner tie rods → tie rod tubes → outer tie rod ends → steering knuckles → wheel. Inner tie rod ends (also called rack ends or inner ball joints) are positioned where the tie rod shaft threads onto or attaches to the rack housing ball stud. These joints must pivot to allow for suspension travel and steering geometry changes. They are subject to high forces and wear, allowing ball stud looseness that directly permits free play in the steering. To check inner tie rod ends, grasp the tie rod as close to the rack boot as possible and push and pull laterally while an assistant turns the steering wheel slightly. Any detectable movement in the inner joint indicates wear. Inner tie rods are also checked by placing a hand on the rack boot and feeling for movement at the joint during steering inputs. While outer tie rod ends, column U-joints, and rack mounting can all contribute to free play, inner tie rod ends are the most common failure point on high-mileage vehicles and should be the first area of investigation. The rack's internal gear mesh can also develop play, requiring rack replacement.
Question 5: A technician is replacing front struts on a vehicle with MacPherson strut suspension. After reassembly, what is the MOST important post-repair step?
- Lubricate the new strut with chassis grease before installation
- Perform a four-wheel alignment (Correct answer)
- Road test to verify strut action before aligning
- Replace the front wheel bearings since they were disturbed during the repair
Correct answer: Perform a four-wheel alignment
MacPherson struts are a structural component of the suspension geometry. Replacing struts changes the ride height and affects camber and caster settings. A complete four-wheel alignment is required after strut replacement to restore proper alignment angles and prevent premature tire wear.
MacPherson strut suspension integrates the shock absorber and spring into a single assembly that also serves as the upper pivot point for the steering knuckle. The strut is connected to the body at the top via the strut mount bearing and to the knuckle at the bottom via the pinch bolt clamp. When the strut is removed and reinstalled, several alignment-critical dimensions can change: the new strut may have slightly different geometry than the old one, the strut mount bearing position changes ride height, and the physical process of removing and reinstalling the assembly can shift the knuckle position. In many designs, the camber angle is partially determined by the strut-to-knuckle mounting position. Even if the new strut appears to be identical to the old one, service manuals universally recommend a wheel alignment after strut replacement. Performing the alignment ensures all four wheels are set to manufacturer specifications, preventing abnormal tire wear and ensuring proper handling characteristics. Additionally, when work is performed on steering and suspension components, the alignment may be affected by loosening and retightening fasteners. Any time the steering linkage or suspension geometry can be changed by a repair, alignment verification is required. Some technicians perform a pre-repair alignment check to document the initial condition.
Question 6: A technician notices that a coil spring on a front strut assembly is cracked at the bottom coil. The customer reports no complaints about handling or ride quality. What should be recommended?
- Monitor the spring for further cracking — replace when the customer notices handling issues
- Replace both front springs as a pair immediately (Correct answer)
- Replace only the cracked spring since the vehicle is riding normally
- Apply epoxy to the crack to restore spring integrity
Correct answer: Replace both front springs as a pair immediately
A cracked coil spring is a safety hazard and must be replaced immediately. Springs can fail suddenly under load and cornering forces, causing unexpected loss of vehicle control. Both springs are replaced as a pair to maintain equal ride height and handling balance.
Coil springs are load-bearing structural components that support the vehicle's weight and maintain proper ride height. A crack in a coil spring is a structural fatigue failure, not a cosmetic issue. The crack concentrates stress and can propagate rapidly, especially when the spring is compressed under the vehicle's weight and additionally loaded during braking, cornering, or hitting a bump. A cracked spring can fail completely with no warning, causing sudden suspension collapse on that corner. This can result in the tire contacting the wheel well, the vehicle dropping to one side, and loss of steering control — potentially causing an accident. The fact that the customer has not noticed symptoms yet is irrelevant to the safety recommendation — many customers do not notice subtle changes in ride height or handling until a component fails completely. Replacing springs in pairs is standard practice for two reasons: springs typically have similar mileage and fatigue history, so if one is cracked, the other is likely near failure. Additionally, using a new spring on one side and a settled (shorter) old spring on the other side creates unequal ride height, which affects alignment angles, particularly camber and caster, as well as vehicle handling characteristics. Epoxy or other repairs to cracked springs are not acceptable — springs must handle tens of thousands of pounds of force repeatedly, and no adhesive repair is appropriate for this application.
ASE Practice Test (A4: Suspension & Steering) 2
A vehicle pulls to the left during hard braking but tracks straight during normal driving.
What is the MOST likely cause?