Rack and Pinion

Rack and Pinion: How Steering Works and All You Need to Know

We all know what a steering wheel is and what it’s for, it’s what makes the car turn! What you might not know is how it actually works and what’s going on when you turn the steering wheel. When you have steering wheel problems, you’ll probably hear the terms “rack and pinion”. If you’re wondering what that is, worry not. We’ll discuss everything about rack and pinion in this post. From how it works, the symptoms of a failing rack and pinion, the replacement costs, and more.

How Does Rack and Pinion Work?

The rack and pinion is basically a gearing mechanism that pushes or pulls the car’s wheels into a direction depending on the direction you turn the steering wheel. As the name suggests, there is a rack (a linear gear) that connects to the tierods. The tierods are connected to steering arms, which are connected to the front wheels. There is also a pinion gear (a circular gear) at the end of your steering wheel, which connects to the steering wheel via the steering column. The pinion gear is connected to the rack and sits on the teeth of the rack.

When you turn the steering wheel, the pinion gear will also turn. This will then move the rack which in turn moves the tierods and the steering arms, and ultimately move the front wheels. For example, when you turn to the left, the pinion gear will turn and move the rack to the left. This moves the tierods and the steering arms, and in turn, the wheels will turn left as well.

Pretty simple, right? But we can’t talk about the rack, pinion, and steering in a car without talking about the power steering mechanism. We’ll focus mostly on the rack and pinion mechanism in this post, but it’ll be good for you to understand how power steering works as well.

How Power Steering Works

Modern cars now have either hydraulic or electric power steering. With hydraulic power steering, there’s a hydraulic actuator or cylinder that will force hydraulic pressure onto the steering gear (the rack and pinion assembly). This helps to apply greater pressure when turning the wheel, making the operation easier for the driver.

The steering wheel operates several valves that control power steering fluid flow into the cylinder. When you turn the wheel, the valves will open accordingly, allowing fluid to flow through and create hydraulic pressure. The fluid itself is exerted from the reservoir through the power steering pump that’s usually powered by the engine’s drive belt. Here’s a quick video explaining how hydraulic power steering works:

Meanwhile, electric power steering works by using an electric motor. This electric motor sits between the steering wheel and steering column and draws energy from the car’s electrical system. There are sensors that detect how much steering the driver is applying. Then, by using this information the computer decides how much assistance the electric motor should give. Note that our explanation is a bit of an oversimplification. You can learn more about rack and pinion and electric power steering in greater detail in this video:

Electric power steering or EPS is slowly becoming the norm as it seems to be more reliable. However, because EPS systems sometimes don’t directly connect the steering wheel and the front wheels, the steering can feel a bit vague. Meanwhile, hydraulic power steering still has a direct connection to the wheel, giving the driver better feedback and feel of what the front wheels are doing. But electric power steering vs hydraulic power steering is a discussion for another day. At least now you know how they work.

Signs Your Rack and Pinion are Failing

Since rack and pinion are basically gear mechanisms, they will wear out and fail over time. Just like almost any other component in your car really. Here are the signs that you will see:

Excessive Play or Loose Steering

Your steering wheel should feel “tight” when you operate it. That is, when you turn the steering wheel, you can feel the front wheels turning. If your rack and pinion are failing, you will notice the steering wheel will start to feel loose or there’s excessive play on the steering wheel. It will often feel like your car is slow to respond when you turn the wheel. The car will also feel more difficult to control and can wander at high speeds.

At some point, you may also feel a numb spot. This is when you turn the steering wheel, but the front wheels aren’t turning until you turn it to a certain angle. This happens because the rack and pinion aren’t gripping each other, which means the rack isn’t actually moving when you turn the wheel.

Noise when Turning

Your car may also make a clunking noise when you turn the steering wheel. A worn-out rack and pinion may not have enough lubrication and are hitting and grinding against each other, making a noise in the process.

Keep in mind that these noises may come from the tierods or other suspension components. The difference is that if the noise stems from a bad rack and pinion, you will hear the noise almost every time you turn the wheel. Meanwhile, clunking noises that come from the suspension assembly usually only happen when you go over bumps or making a tight turn.

Power Steering Leak

car oil leak

If you have hydraulic power steering in your car, you may start seeing a power steering fluid leak when the rack and pinion are failing. If you see a puddle of red fluid under your car, this can either be a power steering leak or a transmission fluid leak. Check where the leak is coming from to verify whether it’s the power steering fluid or the transmission fluid.

Keep in mind that a power steering leak can happen because of a bad power steering pump, faulty reservoir, or leaky lines. Your rack and pinion may not be the cause in the first place. Additionally, if your car has electric power steering, then you won’t see this problem. This is because electric power steering doesn’t require any fluids to operate.

Heavy Steering

This often signifies a hydraulic power steering issue rather than a rack and pinion issue. However, since a bad rack and pinion can cause the power steering fluid to leak, you may see this symptom as well. When the power steering fluid leaks, the system won’t have enough fluid and hydraulic pressure as it normally would. This makes the power steering less effective and ultimately makes steering a lot heavier.

Note that this problem may come from one of the power steering components such as the pump, and not the rack and pinion. If you have electric power steering, you may experience this problem as well when there’s a fault with the system. Diagnosing an electric power steering is rather difficult. Mostly because not all manufacturers have error codes for a power steering fault, so you can’t diagnose them with an OBD scanner. If you’re experiencing power steering issues, we recommend taking your car to a trusted mechanic and have them diagnose the car.

Also, changing your car’s wheel can affect the steering weight, especially if you fit larger and heavier wheels. This is why manufacturers recommend that you go up 2 inches from the original wheels at most when fitting new wheels. Any more than 2 inches can put the steering system under a lot of stress since the wheels are often much heavier. This will ultimately wear out your steering system more quickly.

Before You Replace the Rack and Pinion

When you see the signs above, you’re probably already thinking about replacing the rack and pinion. However, they are very expensive, and we will elaborate on the costs later. The thing is, your car’s steering and suspension assembly are incredibly complex with tons of components that can wear out. Rack and pinion can often be misdiagnosed, resulting in expensive repairs that don’t actually fix the problem.

Before you jump to conclusions and replace the rack and pinion, it’s a good idea to check these other components as well:

Check Your Wheel Alignment

When was the last time you had a good wheel alignment and tire balancing? Bad wheel alignment and unbalanced tires can cause steering issues. A bad wheel alignment can cause the car to pull to the left or right even when you’re driving straight. They can also cause steering noises as well as uneven tire wear. Meanwhile, unbalanced tires can cause the car to vibrate excessively when you go at higher speeds.

While the symptoms are slightly different from a bad rack and pinion, not all of us can tell the difference. Try to remember when was the last time you had a wheel alignment and tire balancing. A wheel alignment should be done every 2 to 3 years, although for better safety you can do it every time you have an oil change. As for tire balancing, this should be done every 12,000 miles or so.

If it’s been a while since your last wheel alignment and tire balancing, then you should try doing them first. Your auto repair shop will usually charge around $100 for a wheel alignment. Meanwhile, tire balancing costs around $20 per tire, which works out to $80 for all four tires. These are higher estimates, they are likely to cost less than the cost we stated for most cars.

If you’ve done a wheel alignment and tire balancing but the symptoms are still there, then it’s time to check the next thing…

Check the Tierods, Struts, and Ball Joints

Rack and Pinion

First, we will need to explain what these components are and what they do. The tierods are a cylindrical steel structure that connects your steering rack to the steering arm. As for struts, they are a structural component that connects the wheel to the vehicle body. It’s a bit of an oversimplification, but they are basically your car’s suspension. Meanwhile, ball joints are spherical bearings that connect the control arms to the steering knuckles.

There are more components in a car’s suspension assembly, and all these components work together to give your car a smooth and stable ride. When one of these components fails, you will notice symptoms similar to a rack and pinion failure. Tierods and balljoint failure will often make a knocking or clunking noise when the car goes over bumps or when you make a tight turn. The car will also feel unstable, and the steering wheel can also feel loose.

Meanwhile, when the struts go bad, your car may be unstable at higher speeds. You will also notice that your car leans forward excessively when you brake. If the rear struts have gone bad, you will notice your car’s rear end bouncing when going over a speed bump.

The symptoms that these components exhibit when they fail are slightly different from a rack and pinion failure. However, some symptoms are similar and it’s a good idea to check them first before replacing your rack and pinion.

Check the Power Steering Pump

Finally, if you have a hydraulic power steering, you’ll want to check the power steering pump. A faulty power steering pump will make the steering wheel heavier and affect the car’s handling. It can also make noises while it operates. To check the pump, you will need a pressure gauge and check the pressure of your power steering pump. A power steering pump should make anywhere between 200 to 1,000 psi of pressure, depending on the manufacturer’s specification.

Additionally, the symptoms you see may be a result of a power steering fluid leak that isn’t related to rack and pinion at all. Find out if there’s a leak in your car, fix the problem, and then see if the symptoms persist. If it does, then you’re likely looking at a rack and pinion problem. We wrote a comprehensive article about power steering fluid leaks and you can read it here.

We also found this great video from Garage Gurus on how to check your power steering pressure:

Rack and Pinion Replacement Cost

Once you verify that the symptoms you’re experiencing aren’t from any of the components above, then it’s very likely you have a rack and pinion problem. As mentioned, a rack and pinion replacement are very expensive, so prepare yourself.

A rack and pinion replacement will cost anywhere between $1,000 – $1,900 including labor, depending on your vehicle’s make and model. The rack and pinion themselves are usually around $700 – $1,500, while labor costs will set you back as high as $400. For example, the rack and pinion for a 2015 Toyota Corolla will cost you $717, add a labor cost of $400 and you’re looking at a repair bill of $1,117.

Of course, these are just rough estimates, and we’re taking the higher end of the spectrum. The rack and pinion replacement for your car may be cheaper than our estimate. Needless to say, luxury and high-performance cars are likely to cost more. The good news is that rack and pinion usually last quite long. They will usually last for about 100,000 miles and they can easily last more than that. My Mitsubishi Pajero Sport for example has done 120,000 miles and is not showing any steering problems.

Can You Do It Yourself?

We will often recommend our readers to do a replacement job themselves to save money on labor costs. However, changing the rack and pinion is a difficult job to do unless you have good mechanical skills and the right tools. So, we don’t actually recommend doing this unless you know what you’re doing.

This is because replacing the rack and pinion requires you to disassemble and remove some of the suspension assemblies to gain access to the rack and pinion themselves. Components that have to be removed include the tierods, the torsion bars, the power steering line, and of course, the rack and pinion assembly themselves. These components can be difficult to access. Not to mention the steps may differ depending on your car’s make and model.

If you do any of the steps incorrectly, this can result in an unsafe vehicle to drive since the steering and suspension assembly is critical to the vehicle’s safety. So, no, we don’t actually recommend you do this yourself. A replacement job this complicated is best left for professional mechanics to deal with.

Here’s a quick video from Scotty Kilmer showing you how to change a steering rack assembly:

Rack and Pinion Replacement Cost: Is It Worth It?

With a replacement job this expensive, you’re probably wondering, is it actually worth it? Before you give your mechanic the go-ahead, it would be wise to check your car’s resale value in the secondhand market. If your car’s value is still well above the repair job, then we would say the cost is worth it.

For example, if the rack and pinion replacement will cost you $1,200, but your car can still be sold at around $10,000, then the repair job is definitely worth it. However, if your car’s resale value is only around $3,000, then it’s not worth it. That’s almost half of your car’s value! In this case, you’re probably better off just selling your car as-is.

Of course, selling your car as-is means reducing your car’s price as you’re leaving the repair job for the next fellow who owns your car to do. But this will at least put cash in your hands rather than taking a hit to your bank account. You can use the money to put a down payment on that car you’ve been eyeing for a while.

Another option would be to scrap your car. You can either take it to a scrapyard or a scrapping company that will pay for your car’s metal value. Or you can also take your car apart and sell individual parts and accessories. The latter is a time-consuming option, but you’re likely to get more money out of your car. Bottom line, don’t proceed with the repairs if your car’s market value isn’t far off from the repair cost.

Can I Drive with a Bad Rack and Pinion?

MINI Cooper D Countryman 2017 11

We can’t stress just how dangerous this is. Once you see the symptoms above and verified that you have a rack and pinion problem, we really don’t recommend you keep driving your car. The rack and pinion are the heart of your car’s steering assembly. When they’re not working properly, you can’t steer your car properly and needless to say, that is incredibly dangerous.

As mentioned, rack and pinion problems will make the car more difficult to control. This can result in a very nasty accident if you’re not careful. It’s going to be like driving an R/C car with the remote control half-dead and the R/C car barely responsive. You’re more likely to crash.

I had a rack and pinion issue in the 1962 Morris Mini Cooper my dad used to own. The problem was so bad to the point the car had a numb spot and the front wheels wouldn’t turn right until I turn the steering wheel almost halfway to the right. It was absolutely frightening, especially at high speeds and I really don’t recommend you drive with a bad rack and pinion unless you absolutely have to.

Rack and Pinion – Wrap Up

So, to summarize, the rack and pinion are the heart of your car’s steering system. The rack is a linear gear that connects to the tierods which are ultimately connected to the front wheels. While the pinion is a round gear that sits on top of the rack and connects to the steering wheel via a steering column.

The rack and pinion will last up until about 100,000 miles. But they can wear out, and when they start to fail, you will see some noticeable symptoms. Some symptoms include clunking noises when you turn the steering wheel, leaking power steering fluid, and a loose steering wheel with a lot of play. This obviously makes steering and car control more difficult. This is why you shouldn’t drive a car with a bad rack and pinion as this can lead to a major accident.

Rack and pinion replacement are quite expensive, ranging from $1,000 to $1,900. Check your car’s resale value before proceeding with repairs to see if the cost is worth it. Once you decide it’s worth it, don’t forget to shop around to find the best quote. Remind your mechanic to inform you of any sudden repairs that aren’t listed in the original quote so you can confirm them first and you won’t have to deal with a repair bill higher than the estimate.

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