Steering Repairs & Suspension Services

The steering system and suspension system work closely together to allow the driver to maintain stability and control of the vehicle. Without steering capability the driver could not change the direction of driving, rendering the vehicle too unsafe. Without the suspension system the vehicle would bounce, buck and vibrate with every irregular surface and pothole in the road. The modern vehicle is not a locomotive, with a track to drive on that dictates its direction. The modern vehicle is an automotive which means it needs autonomous capability to travel over varying surfaces and in any direction the driver sees fit.

Maintenance tip: For front-wheel drive vehicles avoid applying the gas while the wheels are turned at full lock to protect universal joints.

Steering Systems

The steering system converts the rotation of the steering wheel into a swiveling of the front road wheels. There are two types of steering systems. One is called a rack-and-pinion steering system. Another is called a steering box system. Both of these may be supplemented by power steering.

Rack and pinion steering mechanism: 1 steering wheel; 2 steering column; 3 rack and pinion; 4 tie rod; 5 kingpin. CC BY-SA 3.0 LaurensvanLieshout

Rack And Pinion System

The parts of a rack and pinon system include the steering column, universal joint, pinion, rack, tie rod, and kingpin. The pinion is a gear-like part that interlocks with cogs on the rack. When it rotates in one direction it moves the rack to the right. When it rotates in another direction it moves the rack to the left.

Steering Box System

The parts of a steering box system include the steering column, steering box, drop arm, track rod, ball joints, and idler arm. The steering box is similar to a rack and pinion except that instead of using a typical gear-like mechanism, it’s a thread-like mechanism, also called a worm gear. It’s like a screw being driven by a screwdriver.

Power Steering System

Power steering is a system that supplements the steering system and improves the responsiveness of the road wheels to the rotation of the steering wheel. Even if the power steering fails, you’d still have regular steering and could control the vehicle; it would just be a little more challenging. Without power steering it may take several rotations of the steering wheel to turn a corner. Yet with power steering you could potentially make the turn by turning the steering wheel less than one rotation. There are two kinds of power steering systems: hydraulic and electric. Hydraulic steering systems have a hydraulic cylinder and actuator, along with a computer and sensors which are called a servo system. Electric power steering systems have electric motors and actuators.

Speed-dependent 4-wheel steering. CC BY-SA 3.0 Sergey Rufanov

4-Wheel Steering Systems (Quadrasteer)

Traditional steering systems use only the front two wheels. However some vehicles have systems where all 4 wheels can be turned. They have a rear steering unit that sits behind the rear axle and turns the rear wheels in a similar manner as the front wheels. This allows for better handling, especially when turning corners at higher speeds.

The Suspension System

The Suspension system consists of springs, shocks, struts, sway bar or roll bar, ball joints, and spindle. The spring is the main part of the suspension system; it is the part that absorbs the energy of a bump or pothole. Shocks work to dampen the recoil of the springs. The strut connects the springs and shocks. Struts may also be called the upper and lower control arms. The spindle provides a central turning point for the wheel.

Between the steering system, the suspension, the drivetrain and the brakes, there’s a lot going on leading up to the wheels.

Steering & Suspension Maintenance

At Crawford’s Auto repair a full maintenance check is performed with every oil change and at landmark mileage checks (30K, 90K, 150K miles).  The steering and suspension are both inspected during this check, as well as other systems. The check involves a test drive, all fluids check and visual inspection of the entire vehicle both under the hood and with the vehicle raised on hydraulic lifts. During the test drive the technician will note dashboard warning lights or symptoms of vehicle performance which may be related to steering and suspension.

Along with other fluids the power steering fluid is checked. During the visual inspection the technician will check for any leaks that could be coming from the power steering, steering system, sway bar bushings and other moving parts of the suspension (and drive train, brakes, etc.) Any leaks discovered, performance issues, or visual signs of damage would merit further investigation and repairs.

Ball joints and other moving parts are inspected and re-lubricated as needed. It is often suggested that ball joints should be inspected at least twice a year, so checking them with every oil change meets that suggestion. Rack and pinion or gearbox lubrication is performed according to manufacturer’s recommendation.

The power steering fluid level and condition are checked. Belts and hoses are also checked. We may perform a pressure test on the power steering system.

Unlike other systems, a power steering fluid flush is not part of a standard maintenance schedule. Try looking it up in the owner’s manual. It’s not there and don’t let other shops tell you its needed as standard maintenance. If there is damage to the system or contaminants in the fluid from a break in another system, then a flush becomes necessary. See 3 “Standard” Maintenance Services That Are Complete Nonsense.

DIY Maintenance Check: Give a firm, quick single push down a corner of your vehicle. If your vehicle bounces more than twice, then your shocks are worn and need to be serviced.

Power Steering & Suspension Warning Lights

If any of the following lights come on then they will need to be serviced. These symbols are not universal between all makes and models. Your vehicle may have a different variation of one of these lights or it may not have the light at all.

Loose Wheel Light

This light means that you have a loose wheel. How loose? Better find out before you keep driving. This is one that you should memorize if you have it.

Power Steering Lights

If these lights come on it might be a little more challenging to steer but the vehicle can still be driven.

Suspension Indicator Lights

These all mean there is something wrong with the suspension system.

Precision All Wheel Steering System (P-AWS) Indicator

When this light illuminates it indicates that there is a problem with the precision all wheel steering (P-AWS) system and the vehicle may be limited to 50 mph or less.

Other warning lights related to the brakes or drivetrain could also indicate problems with steering and suspension. Your vehicle may also have general warning lights. See the Dashboard Warning Light guide.

Signs Of A Failing Steering System & Power Steering

• Excessive “play” in the steering wheel, meaning steering wheel turns but the road wheels don’t
• A change in steering performance
• The vehicle pulls to one side while driving
• Loose steering when turning the wheel
• Vibration while turning
• A high pitch hum that sounds like a Delorean (the car from the Back To The Future Movies, of course if you’re driving a Delorean that can get confusing)

Signs Of Failing Suspensions

• Suspension bounces more than twice with vehicle corner press test mentioned above
• Car pulls to one side
• Uneven tire wear
• Excessive noise
• Vibration
• Vehicle bounces excessively over bumps
• Vehicle leans hard while turning corners
• Loss of control, car wanders (loose ball joints)
• Clunking noise when turning corners at low speeds

Steering System Repairs

Steering wheel “play” is often caused by worn idler arms or tie-rods. After inspection reveals which is worn or if both are worn the needed repairs would be idler arm replacement or tie-rod replacement.

Sometimes play is also detected in the gear box. This could require worm bearing preload adjustment and over center clearing adjustment.

Lower power steering fluid is often the result of a leak, which is commonly due to hose ruptures. For that we’d perform a power steering hose replacement. The power steering can also under perform if the belt is worn, and for that we’d do a power steering belt replacement. Whenever the power steering system is repaired it will also require a power steering fluid flush, when replacing the fluid a power steering bleed is performed to remove air from the system.

Suspension System Repairs

Springs are made to last for the life of the vehicle and replacement is rare. The shocks can wear over time and could require shock repair. Sometimes the shocks require shock fluid leak repair. Struts may also require strut fluid leak repair. Sway bar bushing replacement is needed whenever the bushings wear out.

Here is a more complete list of steering services & suspension services: