What is a Rack and Pinion?
A rack and pinion assembly helps transfer rotational force from the steering wheel to the front wheels. A steering shaft is attached to the steering column. The steering shaft has a pinion attached which attaches to a linear gear with teeth called the rack. When the steering wheel is rotated, the gear on the shaft turns onto the rack and allows it to grip onto the teeth of the rack, which then turns the wheels. Tie Rods, which help push and pull the wheels when turning, are attached to the Steering Rack at each end.
These days, all cars have either hydraulic or electric power steering. The technology assists rack and pinion operation, thereby reducing the amount of effort required by the driver to turn the front wheels. In a hydraulic system, a power steering pump pressurizes hydraulic fluid to create power assist. On the other hand, if the system is electric, the rack and pinion are driven by an electric motor to provide steering assist.
How Does a Rack and Pinion Break?
There are several reasons why the rack and pinion fail. The first reason is that if there are tears and punctures on the seals attached to the steering rack, the system will not produce the same fluid pressure which will consequently cause fluid leaks, loose steering and/or hard steering. Seals can be replaced, depending on the make and model. A second reason is a lack of maintenance. Depending on the manufacture, intervals of fluid exchange or flushes are highly recommended. Fluids can become contaminated, making it difficult for the fluid to transfer through hoses, which in turn causes the system to work harder, in a similar manner to clogged arteries in our bodies. When the fluid doesn’t flow properly, the system will eventually fail. When contamination occurs, a replacement of the rack, pinion, and even the power steering pump may be needed. A third reason is a failure of the power steering pump. Lastly, normal wear and tear can cause the rack and pinion to break.
How Do I Know if a Rack and Pinion Needs to Be Replaced?
Several signs will occur when the steering rack needs to be replaced. One sign is difficulty with steering at lower speeds. When driving on the highway, loose steering and shaking on the steering wheel are signs of a bad rack. Badly worn tires are another sign. Lastly, a noticeable fluid leak (power steering fluid) is also a sign of replacement.
How Much Does a Rack and Pinion Replacement Cost?
Replacement of a steering rack can cost at least several hundred dollars and as much as over a thousand of dollars. The main reason for this is that often, you must replace multiple parts of the steering rack and pinion component because individual parts cannot be replaced. For example, the power steering fluid flush is needed along with a 4-wheel alignment to prevent wear and to fix alignment. Additionally, labor costs are very high as labor is intense and can take as long as 5 hours with 2 technicians. Generally, the technician will recommend original manufactured part replacements to ensure a good fit, better parts and labor warranty. When finance is a key element of concern, an aftermarket rack will get the job done with a limited warranty option.
What Happens if I Don’t Replace a Rack and Pinion?
If a bad rack and pinion isn’t replaced, your steering will be compromised, which is extremely dangerous.
Do Rack and Pinions Differ by Car?
Nearly all modern vehicles have rack and pinion steering. But on older cars and newer heavy-duty trucks, a steering box is used instead, which is a recirculating ball system, also known as a gearbox.
Can I Replace a Rack and Pinion By Myself?
It is highly recommended to have a professional technician or mechanic perform the replacement if you don’t have mechanical experience or have never replaced a rack and pinion in the past. Unfortunately, there are not any other alternative repairs for a bad rack and pinion. Proper tools, skills and knowledge are necessary.
How Does a Vehicle’s Steering System Work?
The primary function of a vehicle’s steering system is to allow the driver to change the direction of the car when the steering wheel is turned. Your car achieves this by accurately converting the rotational movement of the steering wheel through the steering shaft into angular turning to move the wheels left or right as needed.
A vehicle’s steering system multiplies the steering input via leverage or mechanical advantage to make the wheels of a car easy to turn with minimal effort. The relationship of steering wheel effort to road wheel response is called the steering ratio. The steering ratio for most modern cars is between 12:1 to 20:1 so for every 12-20 degree turn on a steering wheel, the road wheels will turn 1 degree. As this ratio increases, the steering effort required to turn the front wheels decreases.
To make the car turn smoothly, the wheels follow different arcs. The inside wheel follows a circle with a smaller radius to make a tighter turn than the outside wheel. This is possible because of the geometry of the steering linkage.
What Causes Steering Problems?
Although steering systems are relatively simple, they are made up of a lot of parts that are constantly having to perform in perfect unison, and if just one part fails, it can make a huge difference to how your car handles.
Some of the most common steering problems our technicians attend to are:
- Power steering leaks: This presents itself with the loss of power steering which may also be noisy. Power steering fluid can leak from a number of seals, gaskets, or even from the power steering pump itself. Eventually, this causes the power steering pump to fail.
- Excessive play in steering: Characterized by loose steering or excessive free movement felt in the steering wheel, this is typically caused by worn tie rod ends, steering gears, or control arm bushings. Generally, this can be adjusted but sometimes the wear is so bad the entire steering rack unit needs to be replaced.
- Steering wheel shimmy: Shimmy can be best described as the wobbling of the steering wheel on its axis which also can make the front of the vehicle feel like it’s shaking. It can be caused by wheels being misaligned but also worn shock absorbers.
- Vehicle wanders or pulls to one side: This can also be caused by tires being out of alignment but can also indicate worn steering gear.
What Happens When the Power Steering System Fails?
Once a car loses power steering the driver will know about it pretty quickly. A car without power steering will require far more exertion to turn the steering wheel than the driver is used to. This is mostly caused by a loss of power steering fluid but not always. Nonetheless, whatever the cause, the result is the same – a steering wheel that offers too much resistance and a vehicle that’s difficult to turn.
There can be several issues that cause a loss of power steering fluid. The simplest is that the power steering fluid has never been replaced as a part of regular preventative maintenance, or the power steering system is leaking. If fluid has never been replaced, it can be a case of adding fluid and bleeding the system to remove any air. Bleeding the system is imperative to prevent damage to your power steering pump.
Generally, we see three main areas that cause a power steering leak. These are the power steering pump, the power steering hoses, and the steering rack itself. Driving your car without power steering for a short distance is possible but not recommended. Once the power steering pump is dry it will generate excessive heat and friction that can damage the pump.
How to Maintain Your Power Steering System
Keeping an eye on your car’s power steering fluid can prevent a large number of steering issues. A good habit to get into is opening the hood once a month and checking the fluid levels (brake fluid, oil, power steering fluid, etc), and check for any oil leaks or obvious signs of damage. You don’t need any mechanical training to do this, and if you’re unsure of how to go about it, ask your regular mechanic to show you. Also, check the color of the fluids as discoloration also indicates a problem.
Power steering fluid needs to be changed every year or two (depending on what model car you are driving) as it picks up particles and contaminants as it is pumped through the power steering system. If power steering fluid is left unchanged it will eventually accelerate wear on other steering components and restrict fluid flow. The power steering filter should be changed at the same time.
Finally, the belt on the power steering pump should also be inspected about once a month. Power steering belts need to be free of damage like cracks, cuts, tears, and fraying. If you notice any of these the belt is on its way out and needs to be replaced. Another sign of belt wear is a screeching sound coming from the engine bay. There are also additional components to be inspected that are shared with a conventional steering system which we will explain in the next section.
How to Maintain Your Steering System
For a vehicle that doesn’t have power steering, most checks will need to be done by a mechanic although there are still some tasks you can perform yourself to ensure your steering system is up-to-scratch.
Because steering also performs relative to the condition of your vehicle’s tires, wheels should be perfectly aligned and balanced, the tires rotated around every 5,000 miles. Tires can be inspected for signs of abnormal or uneven wear. If any of these are found to be problematic it can affect the steering and handling performance of a vehicle.
Some of the most important steering components like the tie rod ends, ball joints, and idler arms can only be inspected from underneath the vehicle and a wheel jack or car lift is needed to check their condition. Inner and outer tie rod ends are tested by raising the wheel in the air, placing your hands on the 3 o’clock and 9 o’clock position on the tire, and rocking it back and forth to check for any abnormal noises and to ensure the inner and outer tie rod ends are working in synchronicity. A mechanic will also check steering boots and bushing for signs of wear and replace if necessary.
You rely on your vehicle’s steering system every time you drive your car and keeping it working at its very best is as simple as arranging an inspection with our trained technicians. A well-maintained steering system will ensure you can safely handle any bumps in the road and get you where you need to go. Call AutoNation Mobile Service at (877) 907-6484 or book an appointment online to arrange a no-fuss steering inspection.