Suspension and Steering Diagnostics Flashcards

Which measurement should be checked and corrected BEFORE performing a wheel alignment?

Answer: Ride height

Incorrect ride height changes the alignment angles, so it must be correct before alignment.

A rack-and-pinion steering system makes a knocking noise when the steering wheel is turned back and forth at a stop. What is the MOST likely cause?

Answer: Worn rack bushings or loose rack mounts

Worn rack mount bushings let the rack shift and knock during direction changes.

After a four-wheel alignment, the steering wheel is off-center while driving straight. The MOST likely reason is:

Answer: Steering wheel not locked centered while toe was set

Toe must be set with the steering wheel locked straight, or the wheel ends up off-center.

A non-zero thrust angle on a solid rear axle vehicle causes:

Answer: The vehicle to dog-track and the steering wheel to be off-center

The rear axle steers the vehicle to one side, so the front must counter-steer and the steering wheel ends up off-center.

A low-speed shimmy is felt in the steering wheel. Which of these is the MOST likely cause?

Answer: A wheel with excessive radial runout

Runout or a damaged wheel/tire produces a shimmy that you can feel at low speeds.

A hydraulic power steering system groans and the fluid looks foamy. What is the MOST likely cause?

Answer: Air in the system from low fluid or a suction-side leak

Air drawn in through low fluid or a loose suction hose aerates the fluid and makes the pump groan.

A vehicle has electronic stability control. After an alignment or steering repair, what is typically required?

Answer: Steering angle sensor calibration/reset

The steering angle sensor must be zeroed so the stability control system reads straight-ahead correctly.