Have you ever wondered why, when you turn the steering wheel, the rear wheels of your car remain motionless, while the front wheels actively “cut” the arc? This question seems simple only at first glance. In fact, it hides the principles of suspension operation, cornering geometry and even the physics of vehicle movement. In some cases, “sluggishness” of the rear wheels is the norm, but in others it is a sign of a serious malfunction that can lead to an accident.

In this article we will figure out Which wheel does not turn during a standard turn? and why this happens. You will learn how the steering system works, what types of suspensions affect the behavior of the wheels, and when to sound the alarm. We will also answer popular questions: what is the “accordion effect” when turning, why the rear wheels sometimes still turn, and how this relates to drift and the system 4WS (steering with all four wheels).

If you are a novice driver or just an inquisitive car owner, this information will help you better understand your car's behavior on the road. And if you notice that the wheels behave “differently” than usual, here you will find a checklist for diagnosing possible problems.

📊 How often do you pay attention to the behavior of the wheels when turning?
Always important for safety
Sometimes if something goes wrong
I never trust a car
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Why the rear wheels don't turn: basic physics of motion

Let's start with the main thing: During a standard turn in most passenger cars, the rear wheels do not turn. This is due to the steering design, where steering forces are transmitted only to the front axle. The rear wheels in this case follow the trajectory set by the front ones, thanks to tire removal - lateral displacement when moving at an angle.

This operating principle is due to several factors:

  • 🔹 Simplification of design: steering gear only on the front axle is cheaper and more reliable. Additional links and joints for the rear wheels increase weight and the risk of damage.
  • 🔹 Predictability of control: It is easier for the driver to control the car when the rear wheels move along a stable path.
  • 🔹 Reduced tire wear: Constantly turning the rear wheels would lead to uneven wear of the tread.

However, there are exceptions. For example, some sports cars and premium sedans use a 4WS (4-Wheel Steering), where the rear wheels turn at a small angle (1–5°) in the same direction as the front wheels, or in the opposite direction, depending on the speed. This improves maneuverability at high speeds and reduces the turning radius in parking lots.

What is the 4WS system?

The 4WS system (four-wheel steering) first appeared in the 1980s on Honda Prelude and Mazda 626. At low speeds, the rear wheels turn in the opposite direction from the front wheels (reducing the turning radius), and at high speeds they turn in the same direction (increasing stability). Today such a system exists, for example, Porsche 911, BMW 7 Series and Renault Megane RS.

Which wheel does not turn: front or rear?

The answer depends on the type of drive and suspension design:

Vehicle type Which wheels turn Which wheels do NOT turn? Exceptions
Front-wheel drive sedan/hatchback Front Rear 4WS system (rare)
Rear-wheel drive sedan Front Rear Sports models with 4WS
All-wheel drive crossover Front Rear Some models with active steering
Truck/bus Front (sometimes middle axle) Rear (except for the middle axle in multi-axle machines) Special vehicles with multi-axle steering

As can be seen from the table, in 99% of cases rear wheels won't turn. But there are nuances:

  • 🚛 On multi-axle trucks (for example, Volvo FH or Scania R) sometimes not only the front axle, but also the middle axle steers - this reduces tire wear and improves maneuverability.
  • 🏎️ B racing cars (for example, Formula 1 or Le Mans) sometimes use active steering of the rear axle for better cornering.
  • 🚜 On agricultural machinery (tractors, combines) often only the rear axle steers or all wheels synchronously.
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If you are driving a vehicle with 4WS, remember that when parking, the rear wheels may turn in the opposite direction from the front wheels. This is normal and even useful - this way the car turns around almost on the spot!

When is the sluggishness of the rear wheels a breakdown?

Although in most cases it is normal for the rear wheels to remain motionless when turning, there are situations when it indicates a malfunction. Pay attention to the following symptoms:

⚠️ Attention: If, when turning the steering wheel, you hear a creaking, knocking sound, or feel that the rear wheels are “driving” the car to the side, this may be a sign stuck wheel bearing or deformed beam. Check your suspension immediately!

The main reasons for “wrong” sluggishness:

  1. Wheel bearing jamming — the wheel stops rotating freely, which creates a “braking” effect when turning. Often accompanied by a hum at speed.
  2. Damage to levers or silent blocks — if the rear suspension does not maintain its geometry, the wheels can “lead” to the side, simulating a turn.
  3. 4WS system malfunction (if any) - for example, failure of hydraulic cylinders or an electronic control unit.
  4. Deformation of the body or subframe after an accident - changes the angles of the wheels, which is why they “don’t want” to move along the correct trajectory.

How to check? Do a simple test:

Hang the rear axle on a lift or jacks | Spin each wheel manually - it should rotate easily, without jamming | Rock the wheel in a horizontal plane - play of more than 1-2 mm indicates wear of the bearing or silent blocks | Check the temperature of the hubs after the trip - overheating indicates jamming-->

If problems are found, do not delay repairs. For example, a seized bearing can cause wheel coming off while driving, and the deformed beam - to uncontrolled skidding.

How does the steering work: why do only the front wheels turn?

To understand why the rear wheels remain stationary, let's look at how the steering system works. In the classical scheme (for example, on VAZ 2110 or Toyota Corolla) efforts are transmitted as follows:

  1. The driver rotates steering wheel, which is connected through a shaft to steering mechanism (rack or gearbox).
  2. The steering mechanism converts rotation into linear motion steering rods.
  3. The rods turn steering knuckles front wheels through ball joints.
  4. The rear wheels remain in a neutral position, following the trajectory set by the front ones.

The key element here is steering linkage (or Ackermann trapezoid). It provides different turning angles for the inner and outer wheels so that all four wheels roll without slipping. Without it, the tires would quickly wear out, and the car would “float” in corners.

What about the rear wheels? Their position is fixed:

  • 🔧 Beam (in semi-independent suspension, for example, on Renault Logan).
  • 🔧 Multi-link suspension (in independent, as in Volkswagen Golf).
  • 🔧 Bridge (in trucks or SUVs, e.g. UAZ Patriot).

In any case, the rear axle has no connection with the steering mechanism, so its wheels do not respond to steering wheel rotation. The exception is active steering systems, where the rear wheels are controlled by a separate drive (hydraulic or electric).

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The steering linkage is not a piece of hardware, but a precisely calculated mechanism. If after repair the wheel rotation angles do not match, the car will “steer” on its own, especially at high speed.

What is the “accordion effect” and how does it relate to the turning of the wheels?

When turning sharply (for example, at speed or when going around an obstacle), drivers sometimes feel that the car is “compressing” and “stretching” - this is accordion effect. It occurs due to the difference in the trajectories of the front and rear wheels.

Reasons for the effect:

  • 🔄 Different turning radii: the front wheels move in a smaller arc, the rear wheels in a larger arc. This creates a torsional force on the body.
  • 🔄 Tire side pull: At high speeds or low tire pressure, the rear wheels “slide” from the ideal trajectory.
  • 🔄 Incorrect wheel alignment angles: If the rear wheels are at the wrong angle, they “resist” turning.

How does this manifest itself?

  • 🚗 The car “nods off” at the beginning of the turn, and then “straightens out”.
  • 🚗 It feels like the rear wheels are “pulling” in the opposite direction.
  • 🚗 On a wet road there may be rear axle demolition (start of skidding).

To reduce the accordion effect:

⚠️ Attention: If, after replacing tires or repairing the suspension, the car begins to “yaw” in turns, check immediately wheel alignment angles. Even a small deviation (0.5°) can make the car uncontrollable at speeds above 80 km/h.
  • 🔧 Check it out tire pressure (should be the same on one axis).
  • 🔧 Adjust wheel alignment (especially after impacts on the suspension).
  • 🔧 Make sure that shock absorbers and anti-roll bars OK.

Is it possible to modify the car yourself to turn the rear wheels?

Theoretically - yes, practically - this is extremely difficult and dangerous. Active rear axle steering systems (4WS) are factory installed only and require:

  • 🔧 Additional steering rods and drives for the rear wheels.
  • 🔧 Electronic control unit, which will synchronize the turns of the front and rear axles.
  • 🔧 Modified suspension, able to withstand additional loads.
  • 🔧 Certifications (changes made to the design), otherwise the car will not pass inspection.

Attempts to make 4WS with your own hands are fraught with:

  • ❌ Loss of controllability — incorrect angles of rotation of the rear wheels will lead to skidding.
  • ❌ Rapid tire wear — the wheels will “rub” against the road when moving in a straight line.
  • ❌ Accident - a homemade system can jam on the move.

If you really want a car with all-wheel steering, it's better to buy a model with the factory system 4WS. For example:

  • 🚗 Porsche 911 (from 2019) - the rear wheels turn at an angle of up to 3°.
  • 🚗 BMW 7 Series (G70) - system Integral Active Steering with a rear wheel steering angle of up to 3.5°.
  • 🚗 Renault Megane RS — the rear wheels turn by 1° at speeds up to 60 km/h and by 0.5° at high speeds.

These systems not only improve maneuverability, but also increase safety by automatically adjusting the trajectory during emergency maneuvering.

Why do the rear wheels turn when drifting?

When drifting, the rear wheels do not literally turn - they slide at an angle to the direction of travel due to loss of traction. This happens when the driver suddenly releases the gas, blocks the rear wheels with the brake, or redistributes the weight of the car (for example, using the handbrake). As a result, the rear wheels begin to move not forward, but sideways, creating a “turning” effect.

In professional drifting (for example, on Nissan Silvia or Toyota AE86) are often used rear camber angle (up to 5–7°) to improve skid control. But this is not the same as steering - the wheels still do not turn relative to the body.

Can a bad wheel alignment cause the rear wheels to "spin"?

Yes, but not in the literal sense. If the rear wheel alignment angles are incorrect (for example, toe or motion angle), they will not move parallel to the body, but at an angle. This creates the effect that the wheels are “steering” on their own. Signs of a problem:

  • The car pulls to the side when driving in a straight line.
  • Uneven tire wear (for example, “saw” on the tread).
  • The feeling that the rear wheels are “braking” when turning.

The solution is to adjust wheel alignment at the stand. Cost of service: from 1,500 to 3,000 rubles, depending on the type of suspension.

Why does the middle axle sometimes turn on trucks?

On multi-axle trucks (e.g. Volvo FH16 or Mercedes Actros) the middle axis can be steered so that:

  • 🔹Zoom out turning radius (important for maneuverability in the city).
  • 🔹Reduce tire wear — the wheels roll without slipping.
  • 🔹 Boost sustainability at high speed (for example, when overtaking).

Such axles are controlled hydraulically or electrically and rotate up to 10°. The driver can turn the system on/off depending on driving conditions.

What happens if the rear wheels start turning on a regular car?

If on a car without a system 4WS the rear wheels suddenly began to turn, this 100% failure. Possible reasons:

  • 🔧 Broken suspension arm - the wheel “walks” freely.
  • 🔧 Wheel bearing failure - the wheel may “fall” at an angle.
  • 🔧 Beam or subframe deformation after an accident.

Consequences:

  • ❌ The car will become uncontrollable - may spin in place.
  • ❌ Tires will wear out within a few kilometers.
  • ❌ Risk wheel separation on the go.

Driving like this absolutely not possible - Call a tow truck!

How to check if the rear wheels are working properly if they should not turn?

Even if the rear wheels do not turn, their condition is critical for safety. Carry out an inspection:

1. Visually inspect the tires for uneven wear|2. Rock the wheel in the vertical and horizontal planes (no play allowed)|3. Spin the wheel by hand - it should rotate easily, without noise|4. Check the hub temperature after driving (overheating = problem)|5. Inspect the CV joint boots (on all-wheel drive vehicles) for cracks -->

If problems are found, contact service. The average cost of suspension diagnostics: from 1,000 to 2,500 rubles.