Steering and Suspension Lesson Test

Answer: B

Correct answer: Side-to-side linear movement. Rack-and-pinion converts rotary motion into straight-line motion. Turning the steering wheel spins a small pinion gear whose teeth mesh with teeth cut along a straight bar, the rack, so the rack slides left or right. Tie rods on each end push and pull the steering knuckles to turn the wheels. The pinion rotates, but the rack translates; confusing the two is the most common mistake. Up-and-down motion belongs to the suspension.

• A: Incorrect: A brake master cylinder builds brake-fluid pressure and is a separate component.
• B (correct): Correct: The pinion gear rotates and drives a toothed rack sideways to move tie rods.
• C: Incorrect: The wheel hubs rotate with tires; the rack itself translates.
• D: Incorrect: Vertical wheel travel is controlled by suspension links, not the steering rack’s primary action.

Answer: A

Correct answer: A tie rod. The steering rack moves in a straight line, while each wheel pivots on its knuckle, so a link with joints at both ends is needed. The tie rod fills that role, with an inner joint at the rack and an outer tie rod end at the knuckle's steering arm. Its threaded length is adjusted to set toe during an alignment. Worn tie rod ends can cause loose or wandering steering.

• A (correct): Correct: Inner and outer tie rod joints carry rack motion toward the knuckle.
• B: Incorrect: The rotor is a brake-friction component and does not transmit steering linkage motion.
• C: Incorrect: The alternator generates electrical power and is not a steering linkage.
• D: Incorrect: The muffler manages exhaust noise, not wheel direction.

Answer: A

Correct answer: So the wheel is less likely to be pushed toward the driver in a frontal crash. The column carries the steering shaft and switches. It is built to collapse or telescope in a frontal crash so the steering wheel is less likely to be driven toward the driver; many columns also tilt for fit.

• A (correct): The column gives way under crash loads instead of driving the wheel into the driver.
• B: Hydraulic pumps are driven by the engine belt; the column only carries the shaft and switches and drives no pump.
• C: Rack travel is set by the steering gear, not by the column.
• D: Variable assist and ratio come from the gear and assist system, not a collapsing column, whose job is crash protection.

Answer: B

Correct answer: Controlling how fast the spring compresses and rebounds. A shock absorber, more accurately a damper, resists spring motion in both directions. Oil pushed through small valves turns motion energy into heat, so the car settles instead of bouncing and the tires stay on the road.

• A: The springs support the weight of the car and its load; a damper does not hold the car up.
• B (correct): The damper forces oil through valved passages, turning motion into heat so bouncing dies out.
• C: Smooth, low-friction hub rotation is the job of the wheel bearing, not the damper.
• D: Toe is set by adjusting tie rod length.

Answer: B

Correct answer: The wheel tilt seen from the front of the vehicle. Imagine standing in front of the car and looking at a wheel: if the top leans in toward the engine, camber is negative; if it leans out, camber is positive. Camber affects how the tread contacts the road, and too much either way wears one edge of the tire. Students often mix it up with caster, which is the tilt of the steering pivot axis seen from the side, and with toe, which is seen from above.

• A: Incorrect: That describes caster, not camber.
• B (correct): Correct: Camber is the inclination of the wheel itself relative to vertical in front or rear view.
• C: Incorrect: Mass imbalance is addressed by balancing, not camber measurement.
• D: Incorrect: That describes toe, not camber.

Answer: A

Correct answer: The wheel and hub to rotate with low friction. A wheel bearing uses rolling balls or tapered rollers between an inner and outer race, so the hub turns on rolling contact rather than sliding friction. It also carries the vehicle's weight and cornering loads at that corner. A worn bearing typically makes a humming or growling noise that changes with speed and sometimes with turning. It plays no part in steering gears, spring rate or tire tread.

• A (correct): Correct: Bearings support rotating hubs under load while reducing friction.
• B: Incorrect: A conventional coil spring does not use its wheel bearing to adjust rate.
• C: Incorrect: Tread cannot regenerate from hub rotation.
• D: Incorrect: A steering rack does not change transmission gears.

Answer: B

Correct answer: Power-steering assist. Turning tires against the road takes a lot of force, especially when parked or moving slowly. A power-steering system adds force alongside the driver's input, either from hydraulic pressure supplied by a pump or from an electric motor on the column or rack. The mechanical linkage still connects the wheel to the tires; assist only reduces effort. If assist fails, steering becomes much heavier but usually still works.

• A: Incorrect: A cabin filter treats incoming air, not steering effort.
• B (correct): Correct: Hydraulic or electric assist adds steering force or torque, lowering hand effort.
• C: Incorrect: A brake rotor slows wheel spin when pads clamp it.
• D: Incorrect: A speedometer cable transmits speed information rather than assisting steering.

Answer: D

Correct answer: They carry heavy loads and also help locate the axle. A leaf spring is a clamped stack of curved steel strips that bends under load. It suits heavy-duty vehicles because it carries large loads and also locates the axle, though it is heavy and has friction between leaves.

• A: Friction between the leaves is a known drawback.
• B: Weight is one of the drawbacks of leaf springs.
• C: Every spring type still needs damping to control bounce.
• D (correct): A stack of steel leaves supports large loads and positions the axle, so fewer extra links are needed.

Answer: C

Correct answer: From above. Toe compares the front and rear edges of a pair of wheels, so it is seen best looking straight down at the car. If the front edges point slightly toward each other, that is toe-in; if they point apart, toe-out. A useful mental picture is your own feet viewed from above. The other views measure different angles: front view shows camber and side view shows caster.

• A: Incorrect: A front view shows camber, not the key toe relationship.
• B: Incorrect: Steering axis inclination from the side is caster.
• C (correct): Correct: Toe-in or toe-out describes whether wheel leading edges converge or diverge in plan view.
• D: Incorrect: A sidewall number concerns maximum tire pressure, not toe geometry.

Answer: A

Correct answer: Supports a wheel hub and connects steering/suspension joints. The knuckle is the sturdy part at each steered wheel that carries the hub or spindle. Ball joints or a strut mount connect it to the suspension and form the axis it pivots on, while the tie-rod end attaches to its steering arm, so when the tie rod pushes or pulls, the knuckle and wheel swivel. Fuel pumps, airbag modules and oil filters belong to entirely different systems.

• A (correct): Correct: The knuckle carries the hub and pivots through the relevant suspension attachments.
• B: Incorrect: Moving fuel to the injectors is the job of the fuel pump, an engine system part.
• C: Incorrect: An airbag module is a restraint component in the steering wheel and cannot act as a knuckle.
• D: Incorrect: An oil filter removes dirt and metal from lubricating oil; it has no role in holding the hub or joints.

Answer: B

Correct answer: 840 N. Convert first: 24 mm = 0.024 m.

• A: This treats 24 mm as 0.24 m, a decimal-place slip in the conversion.
• B (correct): Convert 24 mm to 0.024 m, then 35,000 × 0.024 = 840 N.
• C: This adds a one-half factor that belongs to the spring energy formula, not to force.
• D: This uses 24 without converting millimeters to meters.

Answer: D

Correct answer: Setting toe within manufacturer specifications. Alignment sets the angles at which the wheels meet the road, mainly camber, caster and toe, by adjusting suspension and steering parts. Balancing is a separate service that spins the wheel and tire assembly and adds weights so its mass is evenly distributed. Suspension repairs can shift the geometry, which is why toe is rechecked afterward. Adding weights is the tempting choice, but that addresses mass, not geometry.

• A: Incorrect: Adding correction weights is wheel balancing.
• B: Incorrect: A valve cap protects the inflation valve but does not adjust geometry.
• C: Incorrect: Battery voltage does not set a steering angle.
• D (correct): Correct: Toe is the geometric orientation of wheels and is a typical alignment parameter.

Answer: B

Correct answer: It resists different amounts of suspension travel between the two sides. An anti-roll bar, also called a sway bar, is a torsion spring connecting the left and right suspension. When both wheels rise together, as over a bump across the lane, the bar barely twists and has little effect. In a turn the outside compresses while the inside extends, so the bar twists and pushes back, reducing body lean. It does not steer, brake or control tire pressure.

• A: Incorrect: Tie rods link the rack to the knuckles to transmit steering input; the bar is not a steering link.
• B (correct): Correct: The stabilizer bar twists as left and right suspension sides move differently and resists roll.
• C: Incorrect: Brake pressure comes from the master cylinder in a separate braking system.
• D: Incorrect: The bar does not control air within tires.

Answer: B

Correct answer: 350°. The ratio is steering-wheel angle divided by road-wheel angle, so steering-wheel angle = ratio × road-wheel angle.

• A: This doubles the result, as if each front wheel needed its own turn of the steering wheel.
• B (correct): Steering-wheel angle equals ratio times road-wheel angle: 14 × 25 = 350°.
• C: This divides 25 by 14, which gives a road-wheel angle from a wheel angle, the reverse of what is asked.
• D: This adds the ratio and the angle instead of multiplying.

Answer: A

Correct answer: An electric motor provides steering assistance based on controller commands. In EPS, a torque sensor in the steering column measures how hard the driver is turning the wheel, and a control module uses that signal, often along with vehicle speed, to command an electric motor on the column or rack. Because no engine-driven hydraulic pump is needed, EPS saves fuel and can vary assist easily. It is separate from the ABS modulator and cannot change how much grip the tires have.

• A (correct): Correct: EPS uses electronic controls and a motor to supplement steering effort.
• B: Incorrect: An electric-assist design gets its assist from a motor and generally does not require a belt-driven hydraulic pump.
• C: Incorrect: The ABS modulator controls brake pressure, not basic steering assist.
• D: Incorrect: Assistance does not create traction or fix slick roads.

Answer: A

Correct answer: Tires, inflation, brake drag and alignment should all be checked first. Pull can have multiple sources; a diagnosis should consider tires, brakes and geometry.

• A (correct): Correct: Pull can have multiple sources; a diagnosis should consider tires, brakes and geometry.
• B: Incorrect: One symptom does not identify a defective rack.
• C: Incorrect: Exhaust parts such as muffler hangers do not set tracking geometry.
• D: Incorrect: Balancing mass does not necessarily correct tire-conicity or alignment pull.

Answer: C

Correct answer: Transmit force while accommodating angular changes during wheel travel. As the suspension moves up and down and the wheels steer, the angle between the tie rod and the knuckle keeps changing. A ball-and-socket joint can pivot in several directions while still pushing and pulling firmly, much like a shoulder joint. That lets steering input reach the wheel at any suspension position. Vehicle weight is carried by springs and ball joints in the suspension, not by the tie rod end.

• A: Incorrect: Primary load support at each corner comes from the suspension springs and structure, not that steering joint.
• B: Incorrect: A tie rod is mechanical linkage, not a fluid reservoir.
• C (correct): Correct: Articulation allows steering motion with suspension displacement.
• D: Incorrect: Drive torque reaches the hub through the axle shafts, not the tie rods, and the hub turns at road-wheel speed.

Answer: D

Correct answer: The dampers. Springs hold the van up, and since it sits at normal height they are doing their job. Continued bouncing and cupped tires mean the dampers no longer control spring motion, so they should be inspected and usually replaced in axle pairs.

• A: Worn tie rod ends cause steering play and wander, not repeated body bouncing.
• B: Imbalance gives a shake at a certain speed band, not bouncing after dips.
• C: Weak springs would let the van sag below normal ride height.
• D (correct): Normal ride height shows the springs are fine; repeated bouncing and cupping point to weak damping.

Answer: C

Correct answer: Caster. Caster is viewed from the side: draw a line through the upper and lower steering pivots, and if its top leans toward the rear of the car, caster is positive. Positive caster helps the wheels return to center and improves straight-line stability, much like the angled fork of a bicycle or the swiveling wheel of a shopping cart. Camber is the tilt of the wheel itself seen from the front, and toe is seen from above.

• A: Incorrect: Camber measures wheel tilt seen from the front.
• B: Incorrect: Toe concerns horizontal wheel pointing viewed from above.
• C (correct): Correct: Caster describes forward/rearward tilt of the steering axis in side view.
• D: Incorrect: Imbalance is a rotational mass distribution issue, not an angle.

Answer: D

Correct answer: Negative. Camber is judged from the front: a wheel whose top leans toward the vehicle's center has negative camber, while one leaning outward has positive camber. Many cars use slight negative camber because body roll in a turn tilts the outside wheel, and starting with some inward lean keeps more tread flat on the road. Too much in either direction wears the tire's inner or outer edge.

• A: Incorrect: Zero camber would place the wheel upright relative to vertical.
• B: Incorrect: Positive camber means the top is tilted outward.
• C: Incorrect: Toe-out is a plan-view steering angle relationship, not camber.
• D (correct): Correct: Inward top tilt is negative camber by the usual convention.

Answer: C

Correct answer: It follows a smaller-radius path than the outside wheel. When a car turns, all four wheels travel around a common center, and the inside wheel is closer to that center, so its arc is tighter. To roll without scrubbing sideways, it must point at a sharper angle than the outside wheel. Ackermann steering geometry achieves this through the angle of the steering arms. A differential lets the wheels turn at different speeds, which is a separate issue from steering angle.

• A: Incorrect: A differential permits speed differences and is not automatically disabled by a steering turn.
• B: Incorrect: Normal turning does not require reverse wheel rotation.
• C (correct): Correct: The inside tire’s path radius is smaller; Ackermann-type geometry accommodates differing trajectories.
• D: Incorrect: Vertical load depends on dynamics and geometry, and this claim is not generally true.

Answer: D

Correct answer: Wheel imbalance is a candidate, while alignment is a separate geometric measurement. An out-of-balance wheel has a heavy spot that tugs the wheel in a circle each revolution; that force grows with speed and often peaks near one speed where the suspension resonates, producing a shake that eases above or below it. Alignment adjusts angles such as toe and camber, which mostly cause pulling or uneven wear rather than vibration. Remembering that balance is mass while alignment is angles keeps the two services separate.

• A: Incorrect: Balance weights correct uneven mass to stop shake; toe is set by tie rod length.
• B: Incorrect: The accelerator pedal is not established as the cause by this symptom.
• C: Incorrect: Many tire, wheel, hub and joint faults can cause vibration, so a broken spring is not confirmed.
• D (correct): Correct: Imbalance can create speed-related vibration; alignment concerns angles and geometry.

Answer: C

Correct answer: A bushing. A bushing is a sleeve, usually rubber or polyurethane, pressed between a suspension arm and its mounting point. It lets the arm pivot through a limited range while absorbing small vibrations and road noise before they reach the body. Worn bushings allow extra movement, leading to clunks, wandering or uneven tire wear. Brake pads and spark plugs are wear parts too, but neither mounts a control arm.

• A: Incorrect: Synchronizers equalize shaft speeds in a manual gearbox.
• B: Incorrect: Spark plugs ignite a gasoline engine mixture.
• C (correct): Correct: Elastomeric bushings allow limited controlled movement and isolate vibration.
• D: Incorrect: Brake pads act on a rotor and do not mount control arms.

Answer: D

Correct answer: Debris and moisture can reach sensitive steering components. Rack boots are flexible accordion-style covers at each end of the steering rack. They seal in the grease on the inner tie rod joints and keep water, salt and grit off the polished rack surface and seals. Once torn, contamination can speed wear on the joint and rack, leading to looseness or leaks, so the boot should be replaced before damage spreads. The boot is purely protective; it is not a spring or part of any other system.

• A: Incorrect: Steering-rack boot damage does not directly establish engine oil pressure.
• B: Incorrect: The protective rack boot is not an air suspension bellows.
• C: Incorrect: The A/C circuit is separate from the rack bellows.
• D (correct): Correct: A torn bellows may expose steering joints or rack surfaces to contamination.

Answer: D

Correct answer: An independent layout allows each side greater freedom of vertical travel. On a solid (beam) axle, both wheels are joined by one rigid member, so a bump under one wheel also tilts and disturbs the other. Independent suspension mounts each wheel on its own linkage, such as control arms or a strut, so one wheel can rise and fall without moving the other, improving ride and grip. Both layouts use springs and shock absorbers, and neither requires four-wheel steering.

• A: Incorrect: Shock absorbers control bouncing with either layout; solid axles commonly use them.
• B: Incorrect: Independent suspension does not imply or require four-wheel steering.
• C: Incorrect: Solid axles commonly use leaf or coil springs.
• D (correct): Correct: Independent wheel movement is the defining architectural difference.

Answer: C

Correct answer: Use the vehicle placard or owner’s manual for cold recommended pressure. The correct cold pressure is chosen by the vehicle maker for that vehicle's weight, handling and braking, and it is printed on the placard, usually on the driver's door jamb, and in the owner's manual. Cold means before driving, since driving heats the air and raises the reading. The number molded on the sidewall is the tire's maximum safe pressure, not the recommended setting, and using it is a common mistake.

• A: Incorrect: Underinflation affects safety, handling and tire life.
• B: Incorrect: Geometric adjustment does not add air to a tire.
• C (correct): Correct: The manufacturer-recommended cold pressure is on the placard or in the manual.
• D: Incorrect: The sidewall marking is usually a maximum, not the vehicle-specific target.

Answer: C

Correct answer: Tread scrubbing and irregular wear. Toe describes whether the wheels point slightly inward or outward. If toe is off, each tire rolls at a small angle to the direction of travel and is dragged sideways a little with every rotation. That scrubbing wears the tread unevenly, often leaving a feathered edge you can feel by running a hand across it. Excess toe can also affect straight-line stability, but it has no effect on engine or electrical systems.

• A: Incorrect: Toe geometry does not transform the material behavior of the spring.
• B: Incorrect: Engine cooling control is independent of wheel toe.
• C (correct): Correct: Excess toe can drag tires slightly sideways while rolling, increasing wear.
• D: Incorrect: Toe does not directly control injector operation.

Answer: A

Correct answer: 50 J. Convert 5 cm to 0.05 m.

• A (correct): $\frac{1}{2}\times 40000\times 0.05^2=50$ J.
• B: This uses 5 instead of 0.05 m, skipping the unit conversion.
• C: This is the spring force kx in newtons, mislabeled as energy.
• D: This leaves out the one-half in the energy formula.

Answer: C

Correct answer: Steering may remain possible but can require substantially more force. Power steering adds force on top of a mechanical connection between the steering wheel and the tires. If the pump, motor or belt fails, that mechanical path remains, so the driver can still steer, but much more effort is needed, especially at low speed. Drivers who lose assist suddenly may think the steering has locked; it has not, it is simply heavy. Assist loss does not change suspension or traction.

• A: Incorrect: Loss of assistance is not identical to joint separation; the wheels stay attached.
• B: Incorrect: The suspension spring constant does not depend on the steering pump and does not double when assist fails.
• C (correct): Correct: Assistance can be lost while mechanical linkage remains; vehicle-specific details apply.
• D: Incorrect: Power-assist loss cannot improve tire-road friction.

Answer: C

Correct answer: Clunking and changed roll control. End links connect each end of the anti-roll bar to the suspension, transferring the twisting force that resists body lean. When their small ball joints or bushings wear, the link develops play, so it knocks or clunks over bumps and the bar responds late, letting the body roll more in turns. A clunk from one corner over small bumps is a classic clue. These links have no role in the engine, battery or transmission.

• A: Incorrect: A chassis link is not an energy-storage battery.
• B: Incorrect: Compression concerns the engine cylinders and seals.
• C (correct): Correct: The link transmits anti-roll bar forces and can knock when worn.
• D: Incorrect: Transmission ratios are determined by gearing, not sway links.

Answer: B

Correct answer: 2,200 N.

A higher center of gravity or narrower track would shift more load.

• A: This multiplies m, a and h but forgets to divide by the track width.
• B (correct): 1,200 × 5 × 0.55 ÷ 1.5 = 2,200 N.
• C: This is just mass times acceleration, ignoring height and track width.
• D: This swaps h and t, multiplying by track width and dividing by height.

Answer: A

Correct answer: 15°. Divide driver input by ratio: 270° / 18 = 15°.

• A (correct): Correct: Divide driver input by ratio: 270° / 18 = 15°.
• B: Incorrect: The number 18 is a dimensionless ratio, not the road-wheel angle.
• C: Incorrect: That would imply 1:1 gearing, not 18:1.
• D: Incorrect: Multiplying 270 by 18 reverses the meaning of the ratio.

Answer: B

Correct answer: 4.0 m.

A longer wheelbase or a smaller wheel angle would widen the turn.

• A: This divides by sin 35° (about 0.57) instead of tan 35°.
• B (correct): R ≈ L ÷ tan δ = 2.8 ÷ 0.70 = 4.0 m.
• C: This multiplies the wheelbase by tan 35° instead of dividing.
• D: This divides by cos 35° (about 0.82) instead of tan 35°.

Answer: D

Correct answer: 3.0 m. Use R≈L/tan(δ); tan45°=1, so R≈3.0 m, at the rear axle center in this simplified model.

• A: Incorrect: 1.5 m results from an arbitrary division by two.
• B: Incorrect: Steering angle in degrees cannot be inserted directly as a length.
• C: Incorrect: 6.0 m results from an unsupported doubling.
• D (correct): Correct: Use R≈L/tan(δ); tan45°=1, so R≈3.0 m, at the rear axle center in this simplified model.

Answer: C

Correct answer: Top of wheel inward, leading edges apart, steering axis rearward at top. Translate each term with its viewing direction. Camber is seen from the front, so negative means the top leans in. Toe is seen from above, so toe-out means the front edges point apart. Caster is seen from the side, so positive means the steering axis top tilts toward the rear. Students often flip a sign or attach a term to the wrong view, which is why linking each angle to its direction helps.

• A: Incorrect: This reverses all three conventions.
• B: Incorrect: Camber and toe observation views are swapped and therefore incorrect.
• C (correct): Correct: Each clause matches its respective angle convention: negative camber, toe-out and positive caster.
• D: Incorrect: Alignment angles are distinct from dynamic rotational mass balance.

Answer: D

Correct answer: 1,600 N. Spring force follows position:

Damper force follows speed:

Since both resist the upward motion, they add to 1,600 N.

• A: This uses 2 instead of 0.02 m for the spring, skipping the unit conversion.
• B: This counts only the damper force and leaves out the spring force.
• C: This subtracts the forces, but both act in the same direction here.
• D (correct): Spring: 30,000 × 0.02 = 600 N. Damper: 2,500 × 0.4 = 1,000 N. Together 1,600 N.

Answer: D

Correct answer: More understeer, with the front tires slipping more and the car pushing wide. In a turn the anti-roll bar twists to resist uneven left-right travel. Making the front bar stiffer tends to increase understeer, meaning the front slips more than the rear,

and the car turns less than the driver steers.

• A: Stiffening the rear bar, not the front, tends to increase oversteer.
• B: The bar does little when both sides move together; it works when one side compresses more, as in a turn.
• C: A bar cannot add grip; it shifts how load and grip are shared between the ends.
• D (correct): A stiffer front bar loads the front tires more in turns, so they reach their limit first.

Answer: A

Correct answer: Tire-generated lateral force is a strong candidate, not alignment alone. Tire construction, such as conicity, can produce a steady side force. A pull that changes direction when tires are swapped points to the tires rather than to alignment alone.

• A (correct): Correct: When the pull follows the tires as they are moved, the tires themselves are producing the side force.
• B: Incorrect: Shock fluid loss is not established by swapping tire locations, and it would not move the pull with the tires.
• C: Incorrect: The symptom does not prove column deformation.
• D: Incorrect: A zero-caster requirement is unsupported; most cars use positive caster, and caster would not follow the tires.

Answer: B

Correct answer: The right front wheel often has a greater steering angle than the left front wheel. In a turn, both front wheels pivot around a common center that lies along the extended rear-axle line. The inside wheel sits closer to that center, so it follows a smaller circle and must be steered more sharply. Ackermann geometry achieves this by angling the steering arms so the inside wheel turns farther than the outside one. Identical angles would force one tire to scrub sideways, which wears tires and makes slow, tight turns feel heavy.

• A: Incorrect: The inside tire still transmits side forces from the road, even at low speed.
• B (correct): Correct: The inside wheel (right wheel in a right turn) traces a tighter path and usually needs more steering angle.
• C: Incorrect: Wheel rotation direction is not normally reversed by a forward turn.
• D: Incorrect: Parallel wheels at identical angles would not match the different turning radii of the inside and outside wheels.

Answer: A

Correct answer: 20° is an idealized average road-wheel angle; real geometry can make the ratio vary. 320° ÷ 16 = 20°, but nonlinear linkage geometry and left-right angle differences limit the simple model.

• A (correct): Correct: 320° ÷ 16 = 20°, but nonlinear linkage geometry and left-right angle differences limit the simple model.
• B: Incorrect: Real vehicles may differ in inside and outside wheel angle, and the steering mapping is not fixed under every load.
• C: Incorrect: Steering angle describes orientation, not rotations around the rolling axle.
• D: Incorrect: A gear ratio has no direct power to determine coefficient of friction.

Answer: A

Correct answer: The strut replacement, because the strut also locates the top of the knuckle. A separate shock absorber only damps; the spring and arms locate the wheel. A MacPherson strut combines the damper with the spring seat and also holds the top of the knuckle in place, so replacing it can change the alignment angles and a check is advised.

• A (correct): A MacPherson strut is a structural link that sets the knuckle position, so swapping it can shift the wheel angles.
• B: A separate shock only damps motion; the springs carry the weight, and changing the shock does not usually move the wheel angles.
• C: This absolute claim ignores that a strut is part of the suspension structure and helps set camber and other angles.
• D: A separate shock mounts between body and arm without setting toe, so the two jobs do not affect alignment equally.

Answer: D

Correct answer: A small round gear on the end of the steering shaft. The steering shaft ends in a small round gear, the pinion. When the driver turns the wheel, the pinion rotates and its teeth drive the toothed rack left or right, which moves the tie rods.

• A: That describes the rack, which the pinion drives.
• B: That is the outer tie rod end, which links the tie rod to the steering arm.
• C: That is the steering arm, the last link before the wheel pivots.
• D (correct): The pinion is the small gear turned by the steering shaft; its teeth push the rack sideways.

Answer: A

Correct answer: 15:1. Convert turns to degrees first: 1.5 × 360° = 540°. Then divide steering-wheel angle by road-wheel angle.

The ratio is 15:1.

• A (correct): One and a half turns is 1.5 × 360° = 540°, and 540° ÷ 36° = 15, so the ratio is 15:1.
• B: This counts only one full turn (360°) instead of one and a half turns.
• C: This counts two full turns (720°) instead of one and a half turns.
• D: This uses half a turn (180°) instead of one and a half full turns.

Answer: D

Correct answer: 48 J. Convert to meters: 4 cm = 0.04 m. Then use the spring-energy formula.

• A: This leaves out the one-half in E = ½kx².
• B: This uses x instead of x², computing ½ × 60,000 × 0.04.
• C: This keeps x in centimeters (4) instead of converting to 0.04 m.
• D (correct): Converting 4 cm to 0.04 m gives ½ × 60,000 × 0.0016 = 48 J.

Answer: A

Correct answer: The springs. Springs support the vehicle's weight and set its ride height. Dampers (shock absorbers) only control the speed of spring motion, which is a common test trap.

• A (correct): Coil, leaf, torsion-bar or air springs hold up the sprung mass and set ride height.
• B: Shock absorbers only control how fast the springs move; they do not hold the car up.
• C: Tie rods transmit steering motion from the rack to the knuckles, not vehicle weight.
• D: Wheel bearings let the hub spin with little friction; the springs above them support the body.

Answer: B

Correct answer: Better straight-line stability and self-centering, with heavier steering. Caster is the side-view tilt of the steering axis; with positive caster its top leans rearward, like a bicycle fork. That helps the wheels self-center and improves straight-line stability, but more of it makes steering heavier.

• A: Adding positive caster does the opposite: it strengthens the return to center after turns and adds steering effort.
• B (correct): Positive caster helps the wheels return to straight ahead and steadies the car, at the cost of extra steering effort.
• C: Shoulder wear from wheel tilt is linked to camber, the tilt seen from the front, not caster.
• D: A speed-band shake points to wheel imbalance, which caster does not change.

Answer: D

Correct answer: A low fluid level letting the pump draw in air. In a hydraulic system, low fluid lets the pump pull in air. Air in the fluid makes it foam, the pump whines, and assist becomes jerky. The repair starts with finding the leak and refilling with the fluid type the maker specifies.

• A: A worn tie rod end adds free play and wander, but it cannot cause pump whine or foamy fluid.
• B: Front wheel imbalance causes a shake at certain road speeds, not changes in the hydraulic fluid.
• C: Camber affects tire wear and wheel tilt, not the condition of the power-steering fluid.
• D (correct): Low fluid lets air enter the pump, which causes whining, foamy fluid and uneven assist.

Answer: B

Correct answer: 3.8 m. The bicycle model treats each axle as a single wheel at its center. The turning center lies on the extended rear-axle line, and the wheelbase and steered angle form a right triangle: tan δ equals L divided by R, so R equals L ÷ tan δ. A larger steering angle means a bigger tangent and a tighter turn. A sanity check helps: since tan 40° is less than 1, the radius must be larger than 3.2 m.

• A: This multiplies the wheelbase by tan 40° instead of dividing by it.
• B (correct): Dividing 3.2 m by 0.84 gives about 3.8 m.
• C: This divides 0.84 by 3.2, turning the formula upside down.
• D: This divides the wheelbase by the angle in degrees (40) instead of by its tangent.

Answer: B

Correct answer: 37.5 J. First find the compression from Hooke's law:

Then find the energy.

As a check, E also equals ½Fx = ½ ×

• A: This multiplies force by compression (1,500 × 0.05) and leaves out the one-half.
• B (correct): Hooke's law gives x = 1,500 ÷ 30,000 = 0.05 m, and ½ × 30,000 × 0.05² = 37.5 J.
• C: This uses the compression as 5 (centimeters) instead of 0.05 m.
• D: This squares 0.05 incorrectly as 0.00025 instead of 0.0025.

Answer: C

Correct answer: 300,000 N/m. Rearrange Hooke's law to

and convert first: 15 mm = 0.015 m.

A sense check: about 300 N for each millimeter of compression is reasonable for a load-carrying spring.

• A: This divides by 15 without converting millimeters to meters.
• B: This converts 15 mm to 0.15 m instead of 0.015 m.
• C (correct): With x = 0.015 m, k = 4,500 ÷ 0.015 = 300,000 N/m.
• D: This multiplies force by compression (4,500 × 15) instead of dividing.

Answer: B

Correct answer: A bump under one wheel tugs more on the other side, making the ride harsher. An anti-roll bar twists when one side compresses more than the other. A thicker bar resists that difference more, cutting lean, but it also ties the two sides together, so a bump under one wheel affects the other and the ride can feel harsher.

• A: An anti-roll bar does not replace dampers; spring motion over rough pavement still has to be damped.
• B (correct): A thicker bar couples left and right more tightly, so one-wheel bumps are passed across and wheels act less independently.
• C: Ride height is set by the springs; the bar does not lift the body and does little when both sides move together.
• D: Free play comes from worn joints and loose mounts in the steering linkage, not bar thickness.

Answer: A

Correct answer: The length of the tie rods, using the threads between inner and outer ends. Toe is the angle of the tires seen from above. The tie rods connect the rack to the knuckles, and the threads between the inner and outer pieces let a technician change their length, which turns each wheel slightly in or out.

• A (correct): Toe is set by turning the threaded tie rod connection to lengthen or shorten each rod.
• B: Balance weights correct uneven mass for a smooth spin; they do not change wheel angles.
• C: Spring seats change ride height and preload, not the direction the wheels point, so toe is not set there.
• D: The anti-roll bar limits body roll and has no role in setting toe.

Answer: C

Correct answer: The pitman arm. In a recirculating-ball box, the worm and rolling balls move a nut that rotates the sector shaft. The pitman arm on that shaft swings the center link, which is supported by the idler arm and connected to the tie rods.

• A: A rack belongs to rack-and-pinion steering, not to a recirculating-ball box.
• B: The idler arm supports the other end of the center link; it is not driven by the sector shaft.
• C (correct): The pitman arm is fixed to the sector shaft and swings the linkage when the shaft rotates.
• D: The strut mount is a suspension part at the top of a strut, not part of the steering box linkage.

Answer: B

Correct answer: 1,000 N. Spring force depends on position: F = kx =

Damper force depends on speed: F = cv =

The total at that instant is 1,000 N.

• A: The spring is still compressed, so it pushes back even when nothing is moving.
• B (correct): The spring gives 25,000 × 0.04 = 1,000 N, and the damper gives 2,200 × 0 = 0 N because velocity is zero.
• C: This treats the 0.04 m compression as a velocity in the damper formula.
• D: This adds the damper coefficient itself as a force instead of multiplying it by velocity.

Answer: C

Correct answer: 3,500 N. In a turn, load moves to the outside tires, so

• A: This uses the original 4,000 N load and ignores the added weight transfer.
• B: This subtracts the transfer, using 3,000 N; the outside tire gains load in a turn.
• C (correct): The tire load becomes 5,000 N, and 0.7 × 5,000 = 3,500 N.
• D: This divides the load by the friction coefficient instead of multiplying.

Answer: C

Correct answer: The car is understeering, and the stability control may brake individual wheels and cut engine power. Understeer means the front tires reach their limit first and the car turns less than the driver steers. Electronic stability control compares steering angle with yaw rate; when they disagree, it brakes individual wheels and may reduce power, but it can never exceed the tires' grip.

• A: The car turning less than asked is understeer, and stability control acts through brakes and engine power, not by steering.
• B: Stability control cannot create grip beyond what the tires can give.
• C (correct): Turning less than steered means the front tires are slipping, and stability control responds with selective braking and power reduction.
• D: Rotating less than requested is understeer, a real event, so a sensor fault is not the best conclusion.

Answer: D

Correct answer: Underinflation. Read the pattern: both outer edges worn suggests underinflation, center wear suggests overinflation, one shoulder suggests camber, and feathered edges suggest toe. Treat it as a clue and confirm by checking the pressure against the vehicle placard.

• A: Overinflation tends to wear the center of the tread, not both edges.
• B: A camber problem usually wears one shoulder, not both edges evenly.
• C: Imbalance is more often linked to cupped scallops and a speed-band shake.
• D (correct): An underinflated tire flexes and rides on its edges, wearing both shoulders.

Answer: B

Correct answer: A front brake rotor and caliper. Sprung mass is everything the springs hold up: body, frame, engine, people and cargo. Unsprung mass moves with the wheel below the springs: tire, wheel, hub, brakes and part of the arms. Less unsprung mass helps the tire follow bumps.

• A: The engine sits on the body or frame above the springs, so it is sprung mass.
• B (correct): The brakes move up and down with the wheel below the springs, so they are unsprung mass.
• C: Occupants and cargo are carried by the springs, so they are sprung mass.
• D: The body is held up by the springs, making it sprung mass.

Answer: A

Correct answer: So the strut and spring can rotate as the wheels are turned. On a steered strut, the whole strut and spring turn with the knuckle as the driver steers. The bearing in the strut mount lets that rotation happen smoothly; a worn mount can cause binding, creaks or a popping sound when steering.

• A (correct): The strut turns with the knuckle during steering, and the bearing lets it rotate smoothly against the body.
• B: The wheel bearing in the knuckle handles hub rotation as the car rolls, not the strut mount.
• C: Damping over bumps happens inside the strut as oil is forced through valves, not in the mount.
• D: Toe is set by tie rod length; the mount bearing does not change it.

Answer: B

Correct answer: feel quicker, needing less wheel rotation but more effort. Steering ratio is steering-wheel angle divided by road-wheel angle. At 12:1, each 12° of steering gives 1° at the tires, versus 20° at 20:1, so the lower ratio is quicker but needs more force.

• A: This describes the higher 20:1 ratio, not the lower 12:1 ratio.
• B (correct): A lower ratio turns the road wheels more per degree of steering, so it is quicker but heavier.
• C: A lower ratio turns the road wheels more, not less, for the same steering input.
• D: A quicker ratio actually raises the effort, so assist is still useful.

Answer: A

Correct answer: The bar twists, and its stiffness resists the twist. A torsion bar is a straight steel rod anchored at one end and attached to a control arm at the other. When the wheel rises, the arm twists the rod, and the rod's twisting stiffness pushes back, much like Hooke's law for rotation.

• A (correct): One end is anchored and the other is attached to a control arm, so wheel travel twists the bar.
• B: That describes an air spring, which uses a rubber bellows filled with air.
• C: That describes a damper, which turns motion into heat.
• D: That describes a leaf spring, not a single straight rod.

Answer: C

Correct answer: 180 J. Energy in a spring is

so it scales with the square of the compression. Going from 3 cm to 9 cm triples x.

• A: This assumes energy grows in direct proportion to compression, but energy depends on x².
• B: This uses the extra 6 cm as a doubling (×4) instead of comparing 9 cm with 3 cm.
• C (correct): Tripling the compression multiplies the energy by 3² = 9, and 20 × 9 = 180 J.
• D: This cubes the factor (3³ = 27) instead of squaring it.

Answer: D

Correct answer: While maneuvering at low speed, such as parking. Drivers need light steering when parking and steadier steering on the highway. Speed-sensitive systems, including electric power steering programmed with a speed signal, give the most assist at low speed and less as speed rises.

• A: Assist is reduced at highway speed so steering feels steadier, not lighter.
• B: Assist level is tied mainly to vehicle speed, not to how hard the brakes are applied.
• C: With the engine off, a hydraulic pump does not run and assist drops, not rises.
• D (correct): Speed-sensitive systems give the most help at a crawl, when turning the wheels takes the most force.

Answer: D

Free play is steering-wheel motion before the road wheels respond, and excess play causes wander. Worn tie rod ends, a worn idler or pitman arm, loose gear mounts, worn ball joints or a loose wheel bearing can each add slack, so the technician checks all of them.

• A: Free play can come from many joints; assuming the gear is the only source may waste money and miss the real wear.
• B: Alignment sets angles but cannot take looseness out of worn joints.
• C: Low fluid causes whine and heavy or jerky steering, not slack between the wheel and tires.
• D (correct): Free play rarely has a single source, so tie rod ends, idler and pitman arms, gear mounts, ball joints and wheel bearings must all be inspected.

Answer: C

Correct answer: A compressor and valves that add or release air in the air springs. An air spring is a rubber bellows filled with compressed air. A compressor and valves change the air amount to raise, lower or level the vehicle, keeping ride height constant under different loads. Dampers are still needed to control motion.

• A: Shock absorbers, even gas-charged ones, control motion; they do not support the load or set ride height.
• B: An anti-roll bar resists uneven left-right travel and does not raise the car.
• C (correct): Adding air raises the support force and releasing it lowers it, so the system can level the car.
• D: Leaf springs, however thick, flatten under load, which lowers the vehicle rather than keeping height constant.

Answer: A

Correct answer: Less body roll, but tires that skip over bumps more, reducing grip and comfort. Spring rate is a compromise. Stiffer springs cut roll and dive on smooth pavement, but on rough ground they let the tire bounce off bumps instead of following them, so grip can drop and the ride becomes harsher.

• A (correct): Stiff springs limit roll, but on rough surfaces the tire cannot follow the bumps as well, so grip and ride suffer.
• B: Stiffer springs can help on smooth roads, but on rough roads they can reduce tire contact.
• C: A stiffer spring compresses less under the same load, so it would not lower the car.
• D: Spring rate strongly affects comfort; dampers only control how fast the springs move, so they do not set comfort alone.

Answer: C

Correct answer: Have a trained technician do it with proper, undamaged equipment and the maker's procedure. A compressed coil spring stores a large amount of energy even when the vehicle is lifted, and careless release can make it fly apart. Spring and strut removal should be done by a trained technician using proper equipment and the manufacturer's procedure, and a vehicle must never be supported by a jack alone.

• A: A compressed spring can release with deadly force, and a vehicle should never rest on a jack alone.
• B: Cutting a loaded spring can release its stored energy violently and is extremely dangerous.
• C (correct): Spring and strut removal stores dangerous energy, so it belongs to trained technicians following the manufacturer's steps.
• D: Even with the wheel hanging, the spring stays compressed and still stores a great deal of energy.