When turning the steering wheel to its extreme position, the driver may notice that the number of turns differs on the left and right, or the total number of turns exceeds the standard one and a half to two turns. Such asymmetry or excessive travel indicates broken marks when installing the rack, faulty power steering valves, or wear on the steering column universal joint. Ignoring this symptom often leads to uneven tire wear, the car pulling to the side and rapid failure of the pump. power steering or electric drive.
Understanding how many turns the steering wheel should make until it stops is critical for the initial diagnosis of the control system. In good condition, this parameter is strictly regulated by the design of a particular model and does not depend on the wishes of the owner. Rotation imbalance is always a signal that it is necessary to intervene in the wheel steering angle settings or replace components steering rack.
Standard RPM Indicators
For most passenger cars with right- or left-hand drive, the full steering angle is 2.5 to 3.5 turns lock to lock. This means that the wheel should turn approximately 1.25–1.75 turns in each direction. However, the exact value depends on the gear ratio steering gear and suspension geometry.
In sports cars with a sharper steering wheel, the number of revolutions can be reduced to 2.2–2.4 to increase the speed of the car's response to the driver's actions. Conversely, in heavy SUVs or trucks this figure is often increased to reduce steering effort during low-speed maneuvers. It is important to consider that modern systems electric power steering (EUR) can programmatically change the gear ratio depending on the speed.
There is the concept of “backlash” or play in the central position, which should not exceed 5–10 degrees. If, with the wheels in a straight position, the steering wheel has free play of more than 15 degrees, this indicates wear on the hinge joints of the rods or the rack itself. Checking the free play is the first step before counting the full revolutions.
- 🚗 Passenger sedans and hatchbacks: usually 2.7–3.2 revolutions in total.
- 🚙 SUVs and crossovers: often 3.0-3.6 turns due to large wheels.
- 🏎️ Sports modifications: 2.2–2.6 turns for sharp entry into turns.
- 🚛 Trucks: can reach 4 or more revolutions without an amplifier.
Symptoms of incorrect speed
If you notice that the steering wheel turns easier in one direction and harder in the other, or the number of turns before the characteristic knock of the stop differs, this is a clear sign of imbalance. Most often, the driver is faced with a situation where 1.5 turns are available in one direction, and only 1 in the other. This leads to the fact that when driving in a straight line, the steering wheel spokes are skewed, and the car can pull to the side.
Another symptom is the lack of a clear focus. Instead of a sharp stop, the driver feels a soft resistance, which may indicate problems with the bypass valves. hydraulic system. In electric boosters, a soft stop may indicate a software failure or a malfunction of the torque sensor.
⚠️ Attention: If you hear a belt whistle or a strong pump hum when you turn the steering wheel all the way, immediately stop holding the steering wheel in the extreme position. Prolonged operation under load at the “stop” leads to rupture of high-pressure hoses or failure of the pump.
Unevenness also appears when the steering wheel is returned to its original position after a turn. A working system should ensure that the wheels self-return to “zero” due to the kinematics of the suspension. If the steering wheel has to be turned by hand or does not return completely, it means that the angle of rotation is not limited correctly or there is friction in the nodes.
Technical Causes of Rotational Imbalance
The main reason for changes in the number of revolutions is incorrect assembly of the unit after repair. If when replacing the steering rack or tips have not been marked, the center position of the wheel is shifted relative to the center position of the rack. As a result, one side gets more movement and the other gets less.
Wear on internal components also plays a role. Wear on the gear and rack teeth leads to an increase in backlash, which is visually perceived as an increase in the number of idle revolutions. In hydraulic systems, a worn torsion bar or a seized distributor spool can create the illusion of a change in stroke.
Problems with the steering column driveshaft are another common factor. If the cardan crosspiece is soured or has play, the transmission of rotation becomes uneven. In some cases, jamming occurs in a certain zone, which creates a feeling of “biting” the steering wheel and changes the overall feeling of the number of revolutions.
| Malfunction | Symptom | Impact on speed |
|---|---|---|
| The rack marks are knocked off | Crooked steering wheel when straight | Asymmetry (1.5 left, 1.0 right) |
| Tooth wear | Knock, backlash | Increase in total stroke (idle) |
| Power steering malfunction | Rumble, tight movement | Lack of clear focus |
| Cardan shaft jamming | Jerks when rotating | Uneven rotation |
Diagnostics and checking the number of revolutions
To accurately determine the number of revolutions, you must turn off the engine (for power steering) or leave the ignition on (for power steering to unlock the steering wheel). The car must be parked on a flat surface with the wheels pointing straight ahead. Fix the initial position of the steering wheel spokes.
Begin to smoothly rotate the steering wheel in one direction until the characteristic hard stop. Count the full revolutions and the last fraction. Record the result. Return to the center position, checking for symmetry, and repeat the procedure on the other side. The difference between the left and right sides should not exceed 5-10 degrees (about 1/10 of a turn).
☑️ Checklist for primary diagnostics
When diagnosing, it is important to distinguish the mechanical stop of the wheels (touching the arch or levers) from the stop of the rack itself. A mechanical stop is often accompanied by a knocking sound, while a rack stop is a soft but irresistible hydraulic or mechanical resistance inside the housing. If the stops are different in nature, the problem may be in the suspension geometry.
Methods for adjustment and troubleshooting
Adjusting the number of revolutions and centering the steering wheel requires lifting the car on a jack or using a lift. The procedure begins by loosening the bolts securing the steering wheel to the shaft (after making marks). The steering rack must be unscrewed all the way in one direction, then, after counting half of the full stroke, set to the middle position.
After installing the rack in the middle position, the wheels are aligned strictly parallel to the body. At this moment, the steering wheel is fixed in the “straight” position and the fastening is tightened. To fine-tune the wheel rotation angles (so that they are the same on the left and right), an alignment stand is used, where the master adjusts the length of the steering rods.
⚠️ Attention: Self-adjustment of steering rods without a wheel alignment stand is prohibited. Even a minimal change in the length of the rod changes the toe angle of the wheels, which will lead to “eating” the rubber in one season and instability on the track.
If the problem is hydraulic, the system may need to be flushed or the bypass valve replaced. In cases with electric power steering, software calibration of the steering angle sensor (SAS) is often required through a diagnostic scanner. Without this procedure, the system may not operate correctly with the ESP and adaptive cruise control functions.
The influence of the type of amplifier on the steering stroke
The type of booster system installed directly affects the feel of the RPM. In classic hydraulic booster (power steering) the stop in the extreme position feels like a soft wall, as the fluid continues to circulate through the bypass valve. The force on the steering wheel at this moment is maximum.
In systems electric booster (EUR), especially with a rack-and-pinion mechanism on the shaft, the emphasis can be more rigid and sharp. Electronics often limit steering angle at high speeds, making the steering wheel "heavier" and reducing effective travel to improve stability. At parking speeds, the EUR, on the contrary, allows you to make a full rotation with one finger.
Modern variable ratio systems (such as Active Steering) physically change the number of revolutions depending on the speed. In a parking lot it can be 2 turns from lock to lock, and on the track it can be virtually “stretched” to 4-5 turns for accuracy. This is normal behavior and not a malfunction.
Consequences of operating with a faulty system
Ignoring the problem with the number of revolutions and steering asymmetry leads to serious consequences. First of all, safety suffers: in an emergency situation, the driver may instinctively turn the steering wheel the usual number of revolutions, but due to a failure, the car will turn less or more than expected, which is fraught with an accident.
Technical wear is also accelerated. Uneven load on the rack seals leads to their squeezing out and oil leakage. Distorted load on wheel bearings and ball joints reduces their service life. In addition, the constant drift of the car forces the driver to constantly adjust the trajectory, which increases fatigue.
In systems with electric steering, an incorrect rotation angle can cause errors in the operation of active safety systems. The steering angle sensor sends incorrect data to the ABS/ESP unit, and the stabilization system may not work correctly or turn off, leaving the car unprotected in a slippery turn.
Steering prevention and care
To maintain the correct operation of the steering mechanism and maintain the factory speed, it is necessary to regularly check the condition of the steering rod boots. A torn boot leads to abrasive contact with the rack shaft, which causes wear and play, which increases the free play of the steering wheel.
Owners of cars with power steering should change the fluid in the system every 60–80 thousand kilometers. Old fluid loses its properties, becomes saturated with metal shavings and can cause valves to jam, which will change the nature of the stop. For the ESD, it is important to check the electrical contacts and the absence of moisture in the area of the steering column.
Avoid hitting the tires when parking near a curb. A strong impact can bend the rod or displace the shaft teeth, which will instantly throw off the settings and change the number of revolutions. After any serious suspension impact, it is recommended to check the wheel alignment and steering condition.
Is it normal for the steering wheel to turn more easily in one direction?
No, this is not normal. In a working system, the force should be symmetrical. The difference may be caused by contamination of the distributor spool, varying degrees of wear on the cuffs, or a violation of the camber/toe adjustments.
Is it possible to set marks on the steering rack yourself?
Theoretically, it is possible if you have access to the shaft and understand the design. However, without special tools and subsequent adjustment of the toe on the stand, this will lead to “eating” the rubber. It's better to leave this to the professionals.
Why is the steering wheel crooked after replacing the rack?
When replacing the rack, the relative position of the shafts is violated. If the new marks are not perfectly aligned with the center position of the wheels, the steering wheel will become crooked. This can be corrected by adjusting the length of the tie rods.
Does tire pressure affect RPM?
Directly - no, the mechanical stroke of the rack does not change. But a severely flat tire has a larger contact patch and rolling resistance, which can cause the steering to feel heavier and the tires to engage sooner due to sidewall deformation.