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ASE T5 Suspension & Steering (Medium/Heavy Truck) study materials
ASE T5 Suspension & Steering (Medium/Heavy Truck) study resources

ASE T5 Suspension & Steering (Medium/Heavy Truck) practice questions

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Question 1Steering Systems Diagnosis and Repair

A medium-duty truck with an integral power steering gear should be serviced with which fluid?

  1. SAE 80W-90 gear lubricant
  2. SAE 15W-40 engine oil
  3. ATF meeting OEM spec Correct answer.
  4. DOT 3 brake fluid

Explanation

Most medium-duty integral power steering systems are filled with automatic transmission fluid or a dedicated hydraulic oil that meets the OEM specification. The fluid must have the correct viscosity and seal-compatible additive package so the pump and gear operate and seal properly.

Question 2Steering Systems Diagnosis and Repair

Excessive steering wheel free play with the wheels pointed straight ahead is most often caused by:

  1. Incorrect caster angle on the steer axle
  2. Worn tie rod and drag link joints Correct answer.
  3. Underinflated front tires on the steer axle
  4. Worn front wheel bearings with excess play

Explanation

Free play is lost motion between the steering wheel and the road wheels, so it comes from wear in the linkage or gear. Worn tie rod ends, drag link ends, and a worn steering gear all allow the wheel to move before the tires respond.

Question 3Steering Systems Diagnosis and Repair

Toe-in on a heavy truck is measured as:

  1. Angle the front wheels turn relative to each other
  2. Inward or outward tilt of the top of the tire
  3. Spacing difference between front and rear of tires Correct answer.
  4. Angle between the steering axis and vertical

Explanation

Toe is a horizontal-plane angle found by comparing the distance between the front of the two steer tires with the distance between the rear of the same tires at spindle height. The difference, converted to degrees or specified as a distance, is the toe setting.

Question 4Steering Systems Diagnosis and Repair

Caster angle is defined as the:

  1. Inward or outward tilt of the top of the wheel
  2. Difference in toe between left and right front wheels
  3. Forward or rearward tilt of the steering axis Correct answer.
  4. Angle between the kingpin centerline and tire centerline

Explanation

Caster is the side-view tilt of the steering axis, with the top of the axis leaning rearward for positive caster. Positive caster gives directional stability and helps the steering return to center after a turn.

Question 5Steering Systems Diagnosis and Repair

The pitman arm is used to:

  1. Connects the two front wheel steering arms together
  2. Mounts the steering gear to the frame rail
  3. Supports the far end of the drag link on the frame
  4. Transfers sector shaft motion to the drag link Correct answer.

Explanation

The pitman arm is splined to the steering gear sector shaft and converts the sector shaft's rotation into linear motion at the drag link. It is a key wear and torque-check point because a loose pitman nut or worn splines add free play.

Question 6Steering Systems Diagnosis and Repair

On a truck with parallelogram steering linkage, the idler arm:

  1. Supports the far end of the drag link Correct answer.
  2. Connects the two steering knuckles together
  3. Holds the kingpin in the axle beam
  4. Is splined to the steering gear sector shaft

Explanation

The idler arm pivots on a bracket attached to the frame on the side opposite the steering gear and carries the far end of the drag link. Its pivot bushings are a common wear point that shows up as steering free play.

Question 7Steering Systems Diagnosis and Repair

A glazed, slipping power steering pump belt will most likely produce:

  1. A squeal when turning at low speed Correct answer.
  2. Excessive steering wheel free play
  3. A fluid leak at the sector shaft seal
  4. A steady increase in steering effort at all speeds

Explanation

Steering effort peaks when the wheels are turned at low engine speed, which is exactly when a slipping belt cannot drive the pump under load. The belt squeals as it slips and assist drops off.

Question 8Steering Systems Diagnosis and Repair

Kingpin inclination (steering axis inclination) is measured as the:

  1. In the horizontal plane at the rear of the tire
  2. Kingpin tilt from vertical in front view Correct answer.
  3. Between the tire centerline and the road surface
  4. With the wheels turned 20 degrees

Explanation

Kingpin inclination is the front-view angle between the kingpin or steering axis and true vertical. It is read with the wheels straight ahead and contributes to directional stability and steering return.

Question 9Steering Systems Diagnosis and Repair

After replacing a power steering pressure hose, the technician should:

  1. Fill the reservoir and drive the truck at highway speed
  2. Cap the reservoir and crank the engine without starting
  3. Fill, run, and cycle steering with wheels raised Correct answer.
  4. Overfill the reservoir to allow for air expansion

Explanation

Air must be purged from the system before the truck goes back into service. Raising the front wheels, running the engine, and cycling the steering lock to lock while checking the fluid level allows the air to work out without aerating the oil.

Question 10Steering Systems Diagnosis and Repair

A truck has normal assist at idle but very little assist at higher engine rpm. Which condition best explains this?

  1. A flow control valve stuck open Correct answer.
  2. A leaking sector shaft seal at the pitman arm
  3. A worn sector shaft bearing in the gear
  4. A restricted return hose at the reservoir

Explanation

The flow control valve limits how much oil the pump sends to the gear as engine speed rises. If it sticks open, excess flow is bypassed back to the reservoir and assist falls off at higher rpm even though idle assist seems normal.

Question 11Steering Systems Diagnosis and Repair

Which component limits the maximum hydraulic pressure in a power steering system?

  1. The flow control orifice in the pump body
  2. The piston seal inside the steering gear
  3. The relief valve in the pump or gear Correct answer.
  4. The check valve in the pump outlet

Explanation

A spring-loaded relief valve opens at a set pressure and bypasses oil so pressure cannot rise high enough to damage hoses, seals, or the gear. The flow control valve regulates volume, while the relief valve caps pressure.

Question 12Steering Systems Diagnosis and Repair

An integral steering gear with excessive over-center preload will most likely cause:

  1. Fluid leaking from the input shaft seal
  2. A pulsation felt in the steering wheel at idle
  3. Hard steering and poor return on center Correct answer.
  4. Loose, wandering steering on the highway

Explanation

Over-center preload is set at the high point of the gear, which corresponds to straight ahead. Setting it too tight makes the gear bind on center, so the driver feels hard steering and the wheel will not return from a turn.

Question 13Steering Systems Diagnosis and Repair

A truck steers hard in both directions. Pump pressure at the gear inlet is within specification and the return hose is not restricted. The most likely cause is:

  1. A leaking pitman shaft seal
  2. A failed flow control valve in the pump
  3. A binding column U-joint or seized kingpin Correct answer.
  4. A low fluid level in the reservoir

Explanation

Once hydraulic supply and return have been proven good, the remaining causes are mechanical binds in the steering column, linkage, or kingpins. Disconnecting and checking each joint isolates the binding component.

Question 14Steering Systems Diagnosis and Repair

A shimmy that appears only in a narrow speed range and is felt in the steering wheel is most often caused by:

  1. A low power steering fluid level
  2. A misadjusted flow control valve
  3. Incorrect caster on the rear axle
  4. Wheel imbalance or runout with worn parts Correct answer.

Explanation

Shimmy is a forced vibration, usually from tire or wheel imbalance, runout, or a bent wheel, that is amplified by looseness in the front-end parts. Repairing the imbalance without addressing the worn parts often lets the shimmy return.

Question 15Steering Systems Diagnosis and Repair

When replacing a drag link, the technician should:

  1. Reuse the cotter pins if they are not broken
  2. Adjust toe-in by turning the drag link
  3. Tighten the ball stud nuts to spec while the stud is spinning
  4. Check link length and that studs seat in the tapers Correct answer.

Explanation

The replacement link must match the original length so the steering wheel stays centered, and each ball stud must seat fully in its tapered hole before the nut is torqued. A stud that spins in the taper will not seat and will work loose.

Question 16Steering Systems Diagnosis and Repair

A tie rod end with a torn boot and noticeable radial play should be:

  1. Replace it and reset toe-in afterward Correct answer.
  2. Tighten the stud nut to remove the play
  3. Packed with grease and returned to service
  4. Replace it only if it causes tire wear

Explanation

Radial play means the socket is worn beyond service limits, and a torn boot lets dirt and water in to accelerate the wear. Replacing the end changes the toe setting, so toe must be reset after installation.

Question 17Steering Systems Diagnosis and Repair

A steering damper on a heavy truck is intended to:

  1. Dampen kickback and road-induced shimmy Correct answer.
  2. Maintain hydraulic pressure during turns
  3. Provide return-to-center force at low speed
  4. Limit the maximum turning angle of the wheels

Explanation

The damper is a shock absorber attached between the axle and the steering linkage that controls rapid steering motions. It reduces kickback over rough roads and suppresses shimmy, but it does not repair the worn parts that cause shimmy.

Question 18Steering Systems Diagnosis and Repair

Turning angle (wheel cut) that is less than specification on one side is most likely caused by:

  1. A bent steering arm or misadjusted stop Correct answer.
  2. Incorrect toe-in on the front axle
  3. Excessive positive caster on that side
  4. Low tire pressure on that side

Explanation

Maximum wheel cut is set mechanically by the steering stop bolt and the geometry of the steering arm and knuckle. A bent arm or a stop that is adjusted too far in limits how far that wheel can turn.

Question 19Steering Systems Diagnosis and Repair

A steering column U-joint that is dry and seized will most often cause:

  1. Excessive free play at the steering wheel
  2. Hard steering or bind at certain angles Correct answer.
  3. A vibration only at highway speed
  4. Fluid leaks at the steering gear

Explanation

A seized U-joint adds mechanical resistance between the wheel and the gear, so effort rises and the steering may bind as the joint passes through certain angles. It can also cause poor returnability.

Question 20Steering Systems Diagnosis and Repair

A power steering pressure hose that is routed against a sharp frame edge should be:

  1. Shorten the hose so it clears the edge
  2. Clamp it tighter against the frame
  3. Reposition or replace it with correct routing Correct answer.
  4. Wrap it with tape and leave it in place

Explanation

High-pressure hose chafing can wear through the reinforcement and cause a sudden loss of assist or a fire risk. The hose must be routed with the correct clips and clearance so it cannot rub.

Question 21Steering Systems Diagnosis and Repair

When setting up an integral steering gear, the correct sequence is to:

  1. Set sector shaft end play with the engine running
  2. Set worm bearing preload, then over-center preload Correct answer.
  3. Set over-center preload first, then worm bearing preload
  4. Set both adjustments with the wheel turned 90 degrees off center

Explanation

Worm bearing preload sets the drag on the input shaft and must be established before the sector mesh is adjusted. Over-center preload is then set at the high point with the gear centered, because that is where the sector and rack piston mesh tightest.

Question 22Steering Systems Diagnosis and Repair

A truck pulls to the left and the left front tire shows a feathered wear pattern. Which combination fits these symptoms?

  1. Excessive positive camber on the left front wheel
  2. Worn rear spring bushings changing thrust angle
  3. Low tire pressure on the right front tire
  4. Toe out of spec combined with a caster split Correct answer.

Explanation

Feathered or sawtooth tire wear is the classic sign of an incorrect toe setting, because the tread is dragged sideways as the tire rolls. A side-to-side caster difference creates a steering pull toward the side with less positive caster.

Question 23Steering Systems Diagnosis and Repair

A truck wanders and needs constant correction, but steering free play and tires are within specification. The most likely cause is:

  1. A faulty flow control valve in the pump
  2. Too much over-center preload in the gear
  3. Low caster or worn kingpin bushings Correct answer.
  4. A restricted return hose at the reservoir

Explanation

With free play eliminated, wander points to a loss of directional stability or to steering geometry that lets the wheels move under load. Insufficient caster removes the self-centering force, and worn kingpin bushings let the knuckle move in ways the alignment cannot control.

Question 24Steering Systems Diagnosis and Repair

A pressure test shows pressure below specification with the relief valve deadheaded, while flow at idle is within specification. The most likely cause is:

  1. A leaking sector shaft seal
  2. A worn pump or relief valve stuck open Correct answer.
  3. A misadjusted over-center preload
  4. Air trapped in the power steering system

Explanation

Deadheading the system closes off the gear so the gauge reads the pump's maximum pressure capability. If that reading is low while idle flow looks normal, the pump is bypassing internally or the relief valve is bleeding off pressure too early.

Question 25Steering Systems Diagnosis and Repair

A truck's steering wheel does not return to center after a turn, and the front tires show no abnormal wear. The most likely cause is:

  1. A low power steering fluid level
  2. Low caster or excessive over-center preload Correct answer.
  3. Worn tie rod ends with excess play
  4. Excessive toe-in on the front axle

Explanation

Returnability comes from caster and kingpin inclination, which lift the front of the vehicle as the wheels turn and let the weight push the steering back to center. A gear set too tight on center, or caster that is too low, overcomes that force and holds the wheel where it was left.

Question 26Steering Systems Diagnosis and Repair

When checking steering wheel free play on a truck equipped with power steering, the technician should:

  1. Raise both front wheels off the floor and stop the engine.
  2. Turn the wheels fully to the left and race the engine.
  3. Set the wheels straight ahead and let the engine idle. Correct answer.
  4. Hold the steering wheel at the 12 o'clock position and pry the shaft.

Explanation

Free play is measured with the steering centered and normal hydraulic assist present, so the wheels are straight ahead and the engine idles. The wheel is turned gently until resistance is felt, and the movement is read at the rim.

Question 27Steering Systems Diagnosis and Repair

When adding fluid to a power steering system, the technician should use:

  1. The fluid type specified by the vehicle manufacturer. Correct answer.
  2. A universal hydraulic fluid mixed with the old fluid.
  3. Any automatic transmission fluid that meets Dexron.
  4. Engine oil with the same viscosity grade as the original fluid.

Explanation

The manufacturer's specified fluid is formulated for the pump seals, hoses, and valving in that system. Using a fluid of the wrong type or mixing fluids can cause seal swelling, foaming, and poor assist.

Question 28Steering Systems Diagnosis and Repair

A power steering pump drive belt that is too loose will most often cause:

  1. A steering wheel that returns too quickly.
  2. Excessive fluid aeration at idle only.
  3. Reduced assist during low-speed turning. Correct answer.
  4. A constant pressure reading above specification.

Explanation

A loose belt slips when the pump demands the most torque, which occurs at low-speed turning and full lock. The result is low pump speed, low flow, and reduced assist.

Question 29Steering Systems Diagnosis and Repair

When installing a pitman arm on a steering gear, the technician should:

  1. Align the timing marks and use a new retaining nut. Correct answer.
  2. Position it at any spline that centers the steering wheel.
  3. Reuse the old retaining nut with thread-locking compound.
  4. Heat the arm to expand the splines before pressing it on.

Explanation

The pitman arm is indexed to the sector shaft, and the timing marks must line up so the gear is centered in its travel. A new retaining nut is used because the original may be a locking or torque-preload type.

Question 30Steering Systems Diagnosis and Repair

Loose steering gear mounting bolts on a heavy truck can cause:

  1. Toe-out on turns greater than specification.
  2. A binding steering column upper bearing.
  3. A steady increase in pump pressure at idle.
  4. Wander and gear movement on the frame. Correct answer.

Explanation

Loose gear mounting bolts allow the gear housing to shift on the frame, producing wander, clunks, and erratic steering. The bolts should be torqued to specification and the frame inspected for cracks or elongation.

Question 31Steering Systems Diagnosis and Repair

After installing a new drag link, the technician should:

  1. Torque the nut to specification and install a new cotter pin. Correct answer.
  2. Leave the cotter pin out if a nylon insert nut is used.
  3. Tighten the ball stud nut until the cotter pin hole lines up.
  4. Back the nut off one full turn to allow stud movement.

Explanation

Steering ball stud nuts are torqued to specification and secured with a new cotter pin; the nut is never backed off to align a hole. If a nylon-insert nut is used, it must be the type specified by the manufacturer.

Question 32Steering Systems Diagnosis and Repair

In a recirculating ball steering gear, the worm shaft drives the sector shaft through:

  1. A hydraulic piston connected to the pitman arm.
  2. A chain and sprocket inside the housing.
  3. Balls that circulate between the worm and nut. Correct answer.
  4. A direct gear mesh between the worm and sector teeth.

Explanation

In a recirculating-ball gear, bearing balls roll between the worm and the ball nut to reduce friction; the nut's teeth then drive the sector shaft.

Question 33Steering Systems Diagnosis and Repair

A power steering system that whines only when the wheels are turned to full lock is most likely:

  1. Misadjusted front wheel toe.
  2. Relieving pressure through the relief valve. Correct answer.
  3. Equipped with a failing steering column bearing.
  4. Low on fluid because of an external leak.

Explanation

At full lock the steering gear stops the flow, pressure rises, and the pump relief valve opens; the resulting whine is normal for many systems.

Question 34Steering Systems Diagnosis and Repair

Excessive sector shaft end play in an integral steering gear is corrected by:

  1. Increasing pump relief pressure at the valve.
  2. Adding shims beneath the gear side cover.
  3. Replacing the pitman arm on the sector shaft.
  4. Turning the sector shaft adjusting screw. Correct answer.

Explanation

Sector shaft end play is adjusted with the screw on the gear side cover, which moves the sector shaft axially to set mesh and end play. It is adjusted after the worm bearing preload.

Question 35Steering Systems Diagnosis and Repair

Worm bearing preload in an integral steering gear is normally adjusted:

  1. By adding fluid to the gear housing.
  2. With the sector shaft disengaged, using shims or a nut. Correct answer.
  3. By turning the sector shaft adjusting screw clockwise.
  4. With the sector shaft engaged and the pitman arm installed.

Explanation

Worm bearing preload is set with the sector shaft disengaged so bearing drag is measured alone; shims or an adjusting nut set the preload. The sector is engaged afterward for the mesh adjustment.

Question 36Steering Systems Diagnosis and Repair

The flow control valve in a power steering pump serves to:

  1. Prevent fluid from returning to the reservoir when hot.
  2. Lock the steering gear when the engine is shut off.
  3. Regulate the volume of fluid delivered to the steering gear. Correct answer.
  4. Limit maximum system pressure when the wheels are at full lock.

Explanation

The flow control valve regulates the volume of oil delivered to the gear so steering response stays consistent as pump speed changes. The separate relief valve limits maximum pressure.

Question 37Steering Systems Diagnosis and Repair

A restricted power steering reservoir filter will most likely cause:

  1. High pressure at the pump outlet at all times.
  2. Fluid leaking from the sector shaft seal.
  3. A firm steering feel with rapid return to center.
  4. Whining and reduced assist, especially when cold. Correct answer.

Explanation

A restricted reservoir filter starves the pump inlet, causing cavitation, whine, and low assist, especially with cold, thick fluid. The filter should be replaced or the reservoir serviced.

Question 38Steering Systems Diagnosis and Repair

Power steering fluid that is foamy and milky after a repair indicates:

  1. The steering gear has excessive over-center preload.
  2. The pump relief valve is stuck closed.
  3. Air is being drawn into the system or trapped after bleeding. Correct answer.
  4. The fluid has absorbed too much heat and should be topped off.

Explanation

Milky, foamy fluid means air is mixed with the oil, either drawn in through a leaking inlet or trapped after service. The system must be bled and the inlet checked for leaks.

Question 39Steering Systems Diagnosis and Repair

A crack in the frame rail at the steering gear mounting holes is dangerous because:

  1. The gear can flex and separate from the frame. Correct answer.
  2. It causes the relief valve to open at low pressure.
  3. It increases pump flow and causes consistently hard steering.
  4. It changes the front toe setting directly.

Explanation

A crack at the steering gear mounting holes weakens the attachment and can let the gear move or separate from the frame, causing loss of steering control. The frame must be repaired before the truck is returned to service.

Question 40Steering Systems Diagnosis and Repair

When tightening a tie rod adjusting sleeve clamp, the technician should:

  1. Leave the clamp loose so the sleeve can self-center.
  2. Position the clamp bolt on the bottom of the sleeve.
  3. Tighten the clamp before setting toe.
  4. Install the clamp gap aligned with the sleeve slot. Correct answer.

Explanation

The clamp gap must align with the slot in the adjusting sleeve so the clamp can squeeze the sleeve onto the tie rod. Toe is set first, then the clamp is torqued.

Question 41Steering Systems Diagnosis and Repair

Turning angle that is excessive on both sides is most often corrected by:

  1. Replacing the steering gear with a faster ratio.
  2. Adjusting the tie rod to increase toe-in.
  3. Increasing caster on the front axle.
  4. Adjusting the steering knuckle stop bolts. Correct answer.

Explanation

Wheel cut is limited by the steering knuckle stop bolts, which are adjusted to the manufacturer's turning-angle specification. Excessive angle on both sides indicates the stops are too far out.

Question 42Steering Systems Diagnosis and Repair

Toe-out on turns (Ackermann angle) is designed to:

  1. Keep both front wheels parallel to each other during straight-ahead driving.
  2. Let the inner wheel follow a tighter radius than the outer wheel. Correct answer.
  3. Reduce steering effort by increasing caster.
  4. Prevent the steering wheel from returning to center.

Explanation

Toe-out on turns lets the inner wheel turn on a smaller radius than the outer wheel because both wheels follow different arcs around the same turn center. This reduces tire scrub.

Question 43Steering Systems Diagnosis and Repair

A worn rag joint in the steering shaft will most often cause:

  1. Excessive steering wheel free play and a clunk. Correct answer.
  2. A steady pull to one side at highway speed.
  3. Feathered wear on the front tires across the tread.
  4. Low power steering pump pressure at idle.

Explanation

A worn rag joint adds lash between the steering wheel and the gear, felt as free play and often a clunk when changing direction. It should be replaced if deteriorated.

Question 44Steering Systems Diagnosis and Repair

A power steering cooler that is internally restricted will most likely cause:

  1. A steering wheel that is difficult to turn only at full lock.
  2. A pressure reading above specification at the pump.
  3. Hard steering only when the engine is cold.
  4. Overheated fluid and reduced assist after prolonged operation. Correct answer.

Explanation

A restricted cooler reduces heat rejection, so the fluid overheats during prolonged operation and assist fades. Cooler restriction can also raise return-side pressure.

Question 45Steering Systems Diagnosis and Repair

A variable-ratio steering gear provides:

  1. A different gear ratio for left and right turns.
  2. Faster near center and slower near full lock. Correct answer.
  3. A ratio that changes continuously with engine speed.
  4. A constant gear ratio from lock to lock.

Explanation

A variable-ratio gear is faster near center for steering response and slower near full lock for control and reduced effort. The ratio changes with sector position, not engine speed.

Question 46Steering Systems Diagnosis and Repair

In many integral steering gears, poppet valves are used to:

  1. Center the steering wheel after a turn.
  2. Recirculate the balls between the worm and nut.
  3. Limit pressure and dampen feel at the end of travel. Correct answer.
  4. Control the flow of fluid from the reservoir to the pump.

Explanation

Poppet valves in the gear open near the end of travel to limit pressure and cushion the end-of-travel feel. They protect the gear and pump when the wheels are held at full lock.

Question 47Steering Systems Diagnosis and Repair

Replacing a steering gear with one of a numerically lower ratio will:

  1. Increase the turning radius of the vehicle.
  2. Increase the number of steering wheel turns lock to lock.
  3. Have no effect on steering effort or turns.
  4. Reduce the number of steering wheel turns lock to lock. Correct answer.

Explanation

A numerically lower ratio, such as 16:1 instead of 20:1, is faster and requires fewer steering wheel turns lock to lock. Steering effort may increase.

Question 48Steering Systems Diagnosis and Repair

A steering system pressure test shows pressure within specification, but flow is below specification at idle and decreases as temperature rises. The most likely cause is:

  1. A worn pump rotor and vanes. Correct answer.
  2. A return hose that is internally restricted.
  3. A relief valve that is stuck open.
  4. A leaking sector shaft lip seal.

Explanation

Low flow that worsens as oil thins points to internal leakage from worn pump rotors, vanes, or clearances. Pressure can still reach specification at deadhead if the relief valve is working.

Question 49Steering Systems Diagnosis and Repair

A steering gear has a leak at the sector shaft seal. After replacing the seal, the technician should also:

  1. Replace the pitman arm nut with a used nut.
  2. Add a stop-leak additive to the fluid.
  3. Check the sector shaft bearing and surface for wear. Correct answer.
  4. Increase the sector shaft end play to prevent recurrence.

Explanation

A sector shaft seal leak is often caused by a worn bearing or a grooved shaft surface, so these must be checked after seal replacement. Otherwise the new seal will leak again.

Question 50Steering Systems Diagnosis and Repair

When performing a dry park check on a heavy truck's steering linkage, the technician is looking for:

  1. Pump pressure at the relief valve.
  2. Front wheel bearing end play.
  3. Tire tread depth at the center of each front tire.
  4. Loose components while a helper turns the wheel. Correct answer.

Explanation

The dry park check is made with the truck stationary, engine running, and a helper turning the wheel while the technician observes the linkage for looseness. It reveals worn tie rod ends, drag links, and pitman arm joints under load.