Steering is one of the key systems of a car, on which safety and controllability directly depend. Without it, the driver would not be able to control the direction of movement, and any trip would turn into chaos. But how exactly does this system work? What mechanisms are hidden behind the steering wheel, and why does it sometimes become “stiff” or start knocking?
In this article we will analyze the steering device from the steering wheel to the wheels, explain the principle of operation of different types of systems (mechanical, hydraulic, electrical), and also talk about typical malfunctions and their symptoms. You will find out what is different steering rack from steering gearhow it works power steering (power steering) and why modern cars are increasingly equipped electric power steering (EPS). The information will be useful to both novice drivers and experienced car owners who want to understand the technical side of their vehicle.
Main steering components
Any steering system, regardless of type, consists of several key elements. Their interaction ensures the transfer of force from the steering wheel to the wheels. Let's look at the main components:
- 🔄 Steering wheel — interface between the driver and the system. Turning the steering wheel initiates the movement of other mechanisms.
- 🔗 Steering column - a shaft connecting the steering wheel to the steering mechanism. Includes universal joints for vibration compensation and steering wheel adjustment.
- ⚙️ Steering gear - converts the rotational movement of the shaft into linear (for a rack) or changes the angle of rotation (for a gearbox). It happens rack and pinion, worm-type or screw.
- 🔄 Steering rods and ends - transmit force from the mechanism to the wheels. They consist of ball joints that allow you to change the angle.
- 🚗 Steering knuckles — are attached to the wheel hubs and rotate them under the influence of rods.
In modern cars, this set is added power steering — hydraulic (power steering), electrical (EPS) or combined. They reduce the effort required to turn the steering wheel, especially at low speeds. For example, without a parking assist, you would have to apply up to 20–25 kg, which is physically difficult for most drivers.
Types of steering mechanisms: rack vs gearbox
The design of the steering mechanism determines how exactly the force from the steering wheel is transmitted to the wheels. There are two main types: rack and pinion and geared (worm or screw). Each has its own advantages and is used depending on the class of the car.
Rack and pinion mechanism - the most common in passenger cars. It consists of a rack that moves inside the housing when a gear connected to the steering shaft rotates. Benefits:
- ✅ Simplicity of design and ease of maintenance.
- ✅ High precision control (minimal backlash).
- ✅ Compact - takes up little space in the engine compartment.
The disadvantage is sensitivity to impacts (for example, when hitting a curb), which can lead to deformation of the rack.
Gear mechanism (worm or screw nut) is more commonly used in trucks and SUVs. Here the force is transmitted through a “worm-sector” or “screw-nut” pair on circulating balls. Pros:
- ✅ High reliability and ability to withstand heavy loads.
- ✅ Less sensitivity to mechanical damage.
The downside is more play and less precise control compared to a rack.
| Parameter | Rack and pinion mechanism | Gear mechanism |
|---|---|---|
| Application | Passenger cars, crossovers | Trucks, SUVs, old models |
| Control precision | High | Average |
| Difficulty of repair | Low | High |
| Sensitivity to shock | High | Low |
If you hear a crunching or squeaking sound when you turn the steering wheel, this may indicate wear on the rack teeth or linkage joints. In this case, diagnostics on the lift is required.
How does power steering work?
Hydraulic power steering (power steering) - a system that makes it easier to turn the steering wheel due to fluid pressure. It consists of:
- 🔄 Power steering pump — creates pressure, driven by a belt from the engine.
- 🔗 Distributor — directs the fluid into the desired cavity of the hydraulic cylinder depending on the rotation of the steering wheel.
- 🔧 Hydraulic cylinder - converts fluid pressure into mechanical force, which helps move the rack or rotate the sector.
- 💧 Liquid reservoir — a reservoir for storing and cooling hydraulic fluid.
Working principle:
- When the steering wheel is turned, the distributor opens a channel for fluid into one of the cavities of the hydraulic cylinder.
- The pump forces fluid, creating pressure on the cylinder piston.
- The piston helps move the rack or rotate the sector, reducing the force on the steering wheel.
- When the steering wheel is returned to neutral, the fluid flows back into the reservoir.
Power steering requires regular maintenance: checking the fluid level (usually ATF or special PSF) and its replacement every 60–80 thousand km. Signs of malfunction:
- 🔴 Increased effort on the steering wheel (especially at low engine speeds).
- 🔴 Noise or howl of the power steering pump.
- 🔴 Liquid leaks under the car (red or brown).
- 🔴 Sharp jerks of the steering wheel when turning.
What happens if you drive with a faulty power steering?
Ignoring problems with power steering can lead to complete failure of the amplifier, which will make the steering wheel “stiff” as in cars without power steering. In the worst case, the pump belt may break or the distributor may jam, which can lead to loss of control at speed.
Electric power steering (EPS): advantages and design
Electric Power Steering (EPS) - a modern alternative to power steering, which uses an electric motor instead of hydraulics. It can be of three types:
- 🔌 Core — the motor is mounted on the steering column (the most compact, but less powerful).
- 🔌 Rack and pinion — the motor is integrated into the steering rack (optimal balance of power and precision).
- 🔌 Spindle — the motor acts on the rack shaft through a belt drive (less commonly used).
Advantages of EPS over power steering:
- ⚡ Energy efficiency - works only when turning the steering wheel, does not constantly take power away from the engine.
- ⚡ Customizability - the electronic control unit (ECU) can change the force depending on the speed (for example, make the steering wheel lighter in a parking lot and heavier on the highway).
- ⚡ Reliability - there are no liquids, hoses or pumps that can leak.
- ⚡ Compact - takes up less space under the hood.
Disadvantages:
- ⚠️ Higher repair costs (electronics and motors are more expensive than hydraulics).
- ⚠️ Sensitivity to overheating (may turn off during prolonged operation at the limit).
Symptoms of EPS malfunction:
- 🔴The indicator lights up
EPSorSteeringon the dashboard. - 🔴 The steering wheel becomes heavier or, conversely, too light (motor failure).
- 🔴 Extraneous sounds (creaking, crackling) when turning.
☑️ Electric power steering diagnostics
Typical steering faults and their symptoms
Any system wears out over time, and steering is no exception. Let's look at the most common problems and their symptoms:
⚠️ Attention: If there is play in the steering wheel while driving (free play of more than 10°), this may indicate critical wear of the steering rods or rack. Operating a vehicle in this condition is dangerous!
- 🔧 Wear of steering tips - manifested by knocking when driving over uneven surfaces and increased play. Requires replacement of hinges.
- 🔧 Leaking rack or power steering pump seals - can be seen from the liquid stains under the car. Leads to a drop in the liquid level and deterioration in the performance of the amplifier.
- 🔧 Steering rack deformation - occurs after strong impacts (for example, an accident or hitting a curb). Symptoms: tight steering wheel, uneven wheel turning.
- 🔧 Wear of rack or worm teeth - manifested by a crunching sound when turning and increased effort.
- 🔧 Power steering pump malfunction - a howl or hum when turning the steering wheel, often accompanied by vibration.
To diagnose steering use:
- 🔧 Visual inspection on the lift (checking backlashes, leaks, condition of anthers).
- 🔧 Computer diagnostics (for EPS and electronic systems).
- 🔧 Checking the pressure in the power steering system (with a pressure gauge).
Average service life of the steering rack - 150–200 thousand km, but it depends on driving style and road quality. For example, off-road driving or frequent collisions with obstacles reduce the resource by 2-3 times.
Regular checking of the steering rod and rack boots (every 10–15 thousand km) prevents the ingress of dirt and moisture, which extends the service life of the mechanisms.
Maintenance and prevention: how to extend the life of your steering system
In order for the steering to serve for a long time, it is enough to follow a few simple rules:
- Check the power steering fluid level (if there is one). The optimal level is between the marks
MINandMAXon the tank. Use only the fluid recommended by the manufacturer (for example, ATF Dexron III or PSF). - Avoid holding the steering wheel in the extreme position for long periods of time (more than 5 seconds). This puts maximum load on the power steering pump and can lead to overheating.
- Check the boots regularly steering rods and racks. Damaged corrugations allow dirt to pass through, which accelerates wear of the hinges.
- Keep an eye on your wheel alignment. Incorrect wheel alignment angles increase the load on the steering mechanisms.
- Don't ignore knocks and backlashes. Even a small play of 2-3 mm can develop into a serious breakdown.
For vehicles with EPS important:
- 🔌 Do not let the battery drain below
11.5V- this may disrupt the ECU settings. - 🔌 Avoid “lighting” from other cars without disconnecting the terminals - voltage surges harm electronics.
⚠️ Attention: When replacing tie rods or tie rod ends, be sure to wheel alignment adjustment. Otherwise, the car will “pull” to the side, and the tires will wear unevenly.
Average steering service cost:
| Service | Cost (RUB) | Frequency |
|---|---|---|
| Replacing power steering fluid | 1 500–3 000 | 60–80 thousand km |
| Replacement of steering tips (pair) | 3 000–6 000 | By wear |
| Steering rack repair | 8 000–20 000 | 150–200 thousand km |
| EPS diagnostics | 1 000–2 500 | When errors occur |
FAQ: Frequently asked questions about steering
Is it possible to drive if power steering fluid is leaking?
Short term - yes, but with caution. Loss of fluid leads to increased steering effort and the risk of pump overheating. Add fluid until the leak is eliminated. If the level drops critically, the pump may fail.
Why does the steering wheel vibrate when braking?
Steering wheel vibration when braking is usually associated with deformation of brake discs or uneven pad wear. Also the reason may be play in steering rods or unbalanced wheels. Diagnostics of the suspension and braking system is required.
What to do if the EPS icon comes on?
Check the fuse first (usually F30 or F40 in the block). If it is working, connect a diagnostic scanner to read errors. Common causes: motor malfunction, broken wiring or ECU failure. In most cases, the amplifier goes into emergency mode and the steering becomes heavier, but control is maintained.
How often should the steering rack be replaced?
The steering rack is repairable unit, and with proper maintenance it can last 200–300 thousand km. Replacement is required only in case of critical wear (case cracks, tooth wear). In most cases it is enough repairs (replacement of oil seals, bushings, anthers) every 100–150 thousand km.
Is it possible to adjust the steering rack yourself?
Some slats have adjusting screw to eliminate backlash. However, without experience, there is a risk of over-tightening the mechanism, which will lead to a tight steering wheel or accelerated wear. If you are not confident in your skills, it is better to contact the service.