Free ASE A4 Exam Flashcards

Disable the supplemental restraint system (SRS) using the vehicle service procedure. Observe its specified reserve-energy discharge time before handling the airbag or column and follow the same service information to re-enable the system.

The intermediate shaft U-joint(s) and flexible coupling. Noise or play localized to the column area points to these connectors between the column and the steering gear.

The column is designed to shorten under crash loading to help manage impact energy. Inspect the column for collapse or damage after a collision using the manufacturer procedure.

Worm bearing preload and sector lash. Lash is clearance in the gear mesh. Some procedures use an on-center rotating-torque reading to set or verify the mesh. Use the vehicle procedure for sequence and limits.

Check the gear for a one-direction internal leak across a seal or in its control valve. Compare the readings to the vehicle procedure before deciding what to replace.

The input shaft seal, where the pinion/input shaft enters the rack housing -- distinct from pump seal leaks or hose-fitting leaks found elsewhere in the system.

Confirm that the rack and wheel are centered and check individual front toe relative to the rear thrust line. Correct the individual toe settings with the wheel held straight, then recheck total toe.

The manufacturer's specified fluid type (ATF in some systems, a dedicated PS fluid in others) -- using the wrong fluid chemistry can swell or harden seals and cause leaks or poor assist.

Air is entrained in the fluid. Check the fluid level and for a source of air entry, then use the vehicle-specific bleeding procedure.

It meters the supply flow to the steering gear and bypasses excess pump output as pump speed increases. A separate relief function limits maximum pressure.

Look up the approved exchange procedure and fluid specification. Maintain the required supply of fluid during the exchange and bleed the system afterward as directed.

Apply the force and check the movement specified by the vehicle maker, while observing the arm and its mounting. Compare measured play with the service limit.

Lost motion at the inner socket indicates looseness. Compare it with the service limit. Excessive play allows toe to vary and can cause wander and uneven wear.

A failing torque sensor (feeds the assist calculation) and a poor ground connection (EPS modules are sensitive to voltage/ground integrity) -- both can produce identical intermittent-assist symptoms.

Maximum assist at low speed for easy parking/maneuvering, reduced assist at highway speed for better road feel and directional stability -- controlled via solenoids, a variable-displacement pump, or an electronic module.

Measure static ride height and inspect the springs. Check the dampers for poor control of how quickly the front compresses and how it settles after braking. Both faults can contribute to dive.

Inspect for tears, separation and abnormal movement. Apply controlled force as specified with the suspension supported in the prescribed position. Rubber deflection can be normal.

Use the service procedure for the spring and joint design. On many SLA designs with the spring acting on the lower arm, support that arm as specified to unload the lower joint. Some wear indicators are checked with normal vehicle load on the joint.

Side-to-side (lateral) axle movement -- without it (or a Watts linkage), the axle can shift laterally during cornering or acceleration, causing unstable handling.

Clamps the individual leaves together and locates the spring on the axle housing -- if it shears, the leaves and spring can shift out of alignment on the axle.

Inspect the U-bolts, shackles, bushings and spring mounts. Use new U-bolts and other fasteners where the service procedure requires them.

False. Allowable movement and test methods vary by design. Compare measured play or the wear indicator reading with the vehicle service criteria.

A sound-looking boot can conceal internal wear. Follow the specified loaded or unloaded test. Some joints have a dedicated visual wear indicator that must be read at normal load.

If transferring the spring, use the approved compressor before removing the center rod nut. Inspect the mount and bearing and replace serviceable parts as needed. A complete preassembled replacement already contains the spring and mount.

Cupping or scalloping. Poor damping lets the wheel oscillate and vary its contact load, making a series of depressions around the tread. Inspect the wheel assembly and suspension for other contributors.

A sagging or broken spring is one possibility. Verify trim height at the specified points on a level surface, and check load, tire size and spring seats before replacing parts.

The suspension sits at a different point in its travel when the ride height is wrong. That can shift camber, toe or other readings. Correct ride height before setting the angles.

Check the stabilizer bar bushings and mounts for looseness that lets the bar shift. Inspect the springs and dampers as well. Dampers mainly affect how quickly the body rolls.

Once the inner sleeve is clamped, suspension motion twists the rubber. Final tightening at the specified trim position avoids extra twist when the vehicle settles.

A worn rear wheel bearing -- since a FWD car's rear wheels aren't driven, a noise present under both acceleration and coasting (not just one) points to the bearing rather than a driveline component.

The outer tread shoulder. Positive camber tilts the top of the wheel outward, which can concentrate wear on the outside edge.

Where both angles are adjustable, a common front sequence is caster, camber, then toe. Recheck linked settings and follow the manufacturer sequence, including rear settings on a four-wheel alignment.

Steering wheel return-to-center after a turn, and steering effort -- more positive caster improves self-centering and directional stability but increases steering effort.

Left, toward the less positive caster. The left-to-right difference is 2 degrees. Compare the readings and allowable split with the vehicle specifications.

Confirm ride height and the measurement, then inspect for shifted mounts, a shifted subframe or bent components. Use only correction procedures approved for that vehicle.

Check toe. Feathering comes from sideways scrub across the tread. Measure individual and total toe to determine which way the wheels are misaligned.

It verifies Ackermann steering geometry -- that the inside wheel turns a sharper angle than the outside wheel during a turn. A bent steering arm can throw this off even when static toe reads perfectly in spec.

SAI is the front-view inclination of the line through the steering pivots from vertical. It contributes to self-centering as steering lifts the body slightly. It is a design angle, usually without a direct adjustment.

Add SAI and signed camber. For example, 13 degrees of SAI plus -1 degree camber yields 12 degrees. Compare SAI and included angle with the manufacturer data to narrow down possible damage.

The angle between the direction the rear wheels are actually pointing and the vehicle's true centerline -- it represents which way the rear of the vehicle is 'pushing.'

Check thrust angle. The net rolling direction of the rear wheels can point away from the geometric centerline even if the total toe is acceptable.

Set cold tire pressures, use a level surface, meet the vehicle loading requirements, and settle the suspension as specified before measuring from the designated points.

Check for binding in the steering linkage, intermediate shaft, steering gear or upper strut bearings. Direction-dependent poor return after a turn points to a part that binds.

Bump steer is unwanted toe change as the suspension moves through compression and rebound. Torque steer is a steering pull under drive torque; unequal-length halfshafts are one possible contributor on FWD vehicles.

Other faults can vary the tread contact load around the tire. Check for imbalance, wheel or tire runout, and looseness in the suspension.

The sidewall, the valve stem (core and base), and the bead-to-wheel seal area -- slow leaks often hide at the valve stem or bead, not just the tread.

Consult the vehicle procedure. Some systems require a position relearn so displayed pressures match the correct corners. Others locate the sensors automatically.

Measure radial and lateral runout at the points specified by the vehicle maker. Radial runout describes out-of-round movement. Lateral runout describes side-to-side wobble. Also consider tire force variation under load.

Single-plane mode corrects net static imbalance, which can make the assembly hop. Two-plane balancing also corrects couple imbalance, which can make it wobble. Use the balancer-indicated weight positions.

Follow the vehicle maker's tightening sequence, often a crisscross pattern, and use a torque wrench to reach the specified value. Even clamping seats the wheel against the hub.