Steering and Suspension A4 Flashcards

Which of the following indicates excessive play between the rack piston and sector on an integral power steering gear?

Answer: Lost motion within steering gear

Excessive play between the rack piston and sector in an integral power steering gear directly results in 'lost motion' within the steering gear. This means the steering wheel can be turned a certain amount before the road wheels begin to respond, leading to a vague, loose, or unresponsive steering feel for the driver.

A technician discovers that the toe-out-on-turns (turning radius) is incorrect during a wheel alignment. The cause could be a bent:

Answer: Steering arm

Toe-out-on-turns, or Ackermann angle, is a critical alignment specification determined by the geometry of the steering arms. If a steering arm is bent, it will alter the relationship between the inner and outer wheel angles during a turn, causing an incorrect toe-out-on-turns condition. The other components listed primarily affect other alignment angles or steering feel, not this specific turning characteristic.

High steering effort is noticed on a sport utility vehicle. Technician X believes it could be a result of a sheared shift tube. Technician Y believes that it’s a misaligned steering column assembly. Who is correct?

Answer: Technician Y

Technician Y is correct. A misaligned steering column assembly can cause binding or increased friction in the steering shaft and its bearings, leading to significantly higher steering effort. Technician X is incorrect; a sheared shift tube affects the transmission's shifting mechanism and would not directly cause high steering effort.

Which operation should be performed first when removing the power steering pump?

Answer: Disconnect the power steering return hose from the remote reservoir or pump and allow the fluid to drain

The first operation when removing a power steering pump is to disconnect the power steering return hose and allow the fluid to drain. This minimizes spills and mess when the pressure and feed hoses are subsequently disconnected. Draining the system beforehand ensures a cleaner and safer removal process.

A bent cradle could cause this difference if suspension components are mounted to the cradle.

Answer: a bent engine cradle.

A bent engine cradle (or subframe) can cause significant differences in suspension geometry because it provides mounting points for the engine, transmission, and often critical suspension components. If the cradle is bent, these mounting points will be misaligned, leading to uneven suspension component positioning and various handling or alignment issues.

On a short arm long arm (SLA) suspension when replacing a lower control arm bushings, the replacement should be:

Answer: Torqued with vehicle weight on suspension

When replacing lower control arm bushings on an SLA suspension, they must be torqued with the vehicle's weight on the suspension, at its normal ride height. If torqued with the suspension hanging freely, the bushings will be pre-stressed or twisted when the vehicle is lowered, leading to premature wear, noise, and restricted suspension travel. This ensures the bushings are in their neutral operating position.

When aligning a light truck with a torsion bar front suspension, which of these should the technician do first?

Answer: Check/adjust the ride height (curb height)

On vehicles with torsion bar front suspensions, ride height (or curb height) directly influences alignment angles such as caster and camber. Therefore, it is crucial to check and adjust the ride height to the manufacturer's specifications *before* attempting any other alignment adjustments. Failing to do so will result in inaccurate alignment readings and improper adjustments.

Which of these is the least likely cause of vibration in the steering wheel if the vehicle is traveling at 40 mph?

Answer: Worn control arm bushings

Worn control arm bushings are the least likely cause of a distinct vibration in the steering wheel specifically at 40 mph. While worn bushings can cause clunking, wandering, or uneven tire wear, vibrations at specific speeds are more commonly associated with rotating components like bent wheels, shifted tire belts, or improper wheel balance. These issues directly create dynamic imbalances that manifest as speed-sensitive vibrations.

Which procedure should be performed first to remove the manual steering gear (non-rack-and-pinion type)?

Answer: Disconnect the battery ground cable.

Disconnecting the battery ground cable is the essential first step before working on any part of the steering column, especially in modern vehicles. This is a crucial safety precaution to prevent accidental deployment of the airbag, which is typically housed in the steering wheel, or to avoid short circuits in the vehicle's electrical system during the removal process.

The ride height of the front suspension is lower than that of a MacPHerson strut suspension system. The cause of this problem could be any of the following except:

Answer: worn steering gear mounting bushings.

Worn steering gear mounting bushings would primarily cause play or looseness in the steering, or potentially noise, but they would not directly affect the ride height of a MacPherson strut suspension system. Ride height issues are typically caused by components that support the vehicle's weight, such as worn-out struts, springs, or lower control arm bushings.

Which of the following is the most likely indication of a worn control arm bushing?

Answer: Rubber bushing is cracked

A cracked rubber bushing is the most direct and definitive indication of a worn control arm bushing. The rubber material is designed to absorb shock and allow controlled movement, and visible cracking, tearing, or deterioration signifies that the bushing has lost its integrity and can no longer perform its function effectively. While other symptoms like noise or handling issues can occur, a cracked bushing is a clear physical sign of failure.

If not done according to the manufacturer's specifications, any of these could result in tire wear. EXCEPT:

Answer: Caster

Caster primarily affects steering stability, effort, and the steering wheel's returnability, but it has the least direct impact on tire wear compared to toe and camber. Incorrect toe causes the tires to scrub sideways, leading to feathering, while incorrect camber causes wear on one edge of the tire. Although extreme caster can indirectly affect wear by altering camber during turns, it is not a primary cause of tire wear in the same way toe and camber are.

Technician X states that a misaligned steering column input can result in noise. Technician Y states that if the linkage-assist type power steering column is low on lubricant, there is noise while turning the wheel. Who is correct?

Answer: Both technicians

Both technicians are correct. Technician X is right because a misaligned steering column input can cause binding, rubbing, or excessive friction, leading to various noises, especially when turning the wheel. Technician Y is also correct as linkage-assist power steering systems rely on proper lubrication, and low lubricant can cause increased friction and noise, such as groaning or squealing, when the steering wheel is turned.

Technician X says front wheel setback is usually caused by worn suspension components. Technician Y says a slight front wheel setback causes steering pull. Who is right?

Answer: Neither X nor Y

Neither technician is entirely correct. Technician X is wrong because front wheel setback is typically caused by structural damage or bent frame components, not usually by worn suspension components alone. Technician Y is also incorrect because while a significant front wheel setback can cause a steering pull due to altered caster and wheelbase, a 'slight' setback might not always result in a perceptible pull, or the pull might be an indirect effect of other alignment changes rather than the setback itself being the direct cause.

Two technicians are discussing the ride height measuring procedure. Technician X says bent components can cause incorrect ride height. Technician Y says for proper measurement of the ride height, the vehicle must have a full tank of fuel. Who is right?

Answer: Both X and Y

Both Technician X and Y are correct. Technician X is right because bent suspension components or frame damage can directly alter the vehicle's geometry, leading to an incorrect ride height. Technician Y is also correct; for accurate ride height measurements, the vehicle must be in its normal operating condition, which includes having a full tank of fuel, as fuel weight significantly impacts the vehicle's settled height.

Which of the following applies when a shock absorber needs to be replaced due to a fluid leak?

Answer: It fails the bounce test.

While a fluid leak is a clear indication that a shock absorber needs replacement, the most common and practical diagnostic test for functional failure is the 'bounce test.' If the vehicle continues to bounce excessively after being pushed down and released, it indicates that the shock absorber is no longer effectively dampening suspension oscillations, regardless of a visible leak.

A vehicle wanders while being driven on level roads. Technician X says that too much negative camber could be the cause. Technician Y says that too much positive caster could be the cause. Who is right?

Answer: Neither X nor Y

Neither Technician X nor Y is correct. Technician X is wrong because too much negative camber causes the top of the wheel to lean inward, leading to inner tire wear and potentially a pull towards the side with more negative camber, but it does not typically cause wandering. Technician Y is also wrong; too much positive caster actually improves straight-line stability and makes the steering heavier, thus reducing wandering, not causing it. Wandering is usually associated with insufficient caster, excessive toe, or worn steering/suspension components.

While working on a steering column, Technician X says you must consult the online service information to get the proper airbag disabling procedure. Technician Y says that the flexible coupling or U-joint needs to be taken off before you remove the steering wheel. Who is correct?

Answer: Technician X

Technician X is correct. Airbag systems are safety-critical components, and their disabling procedures can vary significantly between manufacturers and models. It is absolutely essential to consult the specific online service information to ensure the correct and safe procedure is followed, preventing accidental deployment or injury. Technician Y is incorrect; the flexible coupling or U-joint connects the steering column to the steering gear, while the steering wheel is at the top of the column and is removed before the coupling.

On a truck with a long-and-short arm front suspension and a leaf spring rear suspension, the steering pulls to the right while driving straight ahead. All of the following defects could be the cause of the problem EXCEPT:

Answer: Excessive toe-in on the front wheels.

Technician X is correct. Worn rack-to-frame mounting bushings allow the entire rack and pinion assembly to move or shift relative to the vehicle's frame. This looseness can cause a shimmy or vibration in the steering wheel, as the steering gear is not rigidly held in place. Technician Y is incorrect; a binding steering shaft U-joint would typically cause increased steering effort or a 'notchy' feel when turning, not a shimmy.

Which of the following location is the steering wheel sensor typically located?

Answer: Base of the steering column

The steering wheel sensor, also known as the steering angle sensor, is typically located at the base of the steering column. It is often integrated into the clock spring assembly behind the steering wheel. This strategic placement allows it to accurately measure the rotational angle of the steering wheel, providing crucial input for systems like electronic stability control (ESC) and electric power steering (EPS).