The appearance of extraneous sounds in the front suspension is always an alarming signal that cannot be ignored. If you notice that there is grinding noise when turning the steering wheel to the left, this indicates critical wear of the units or a violation of their geometry. Unlike dull knocks, which can indicate play, it is the grinding sound that often indicates metal-to-metal friction or damage to the protective elements that allow abrasive to pass through.
Diagnostics must be carried out immediately, since further operation of the vehicle with a faulty suspension can lead to wheel jamming or complete loss of controllability. Most often, drivers confuse crunching, squeaking and grinding, but the nature of these sounds is radically different. Grinding is a high-frequency sound that occurs during hard mechanical contact, whereas crunch usually has a softer, rolling structure, characteristic of constant velocity joints.
In this article, we will analyze in detail all the possible reasons for the occurrence of a metallic sound when turning left, consider the design features of various types of suspensions and determine the algorithm of actions for the owner. Understanding the source of the noise will allow you not only to save on diagnostics at the service center, but also to protect yourself from sudden breakdowns on the highway.
The main causes of metallic grinding noises
The first thing that comes to mind when hearing sounds in the front end is CV joint (constant velocity joint). Indeed, wear and tear of the grenade is one of the most common causes. However, if the grinding noise is heard precisely when the steering wheel is turned to the left, and the car is moving at low speed or is standing still, the range of problems narrows. The inner or outer joint usually makes a characteristic cracking or crunching noise under load while in motion, rather than a static grinding noise.
The more likely reason in this case is support bearing shock absorber strut. This unit ensures smooth rotation of the shock absorber rod along with the spring when turning the wheels. When the bearing cage breaks down or the lubricant dries out, the metal elements begin to rub against each other, producing a high-pitched grinding noise. This is especially noticeable in a cold car or during sudden steering movements.
Another sound source could be braking system. If, when turning the car body (which happens when the steering wheel is shifted), the caliper or pad touches the disc, you will hear a grinding noise. This may be caused by a warped brake disc, worn caliper guides, or a foreign object between the disc and the guard.
Diagnostics of support bearing and struts
The support bearing is the connecting link between the shock absorber and the car body. It bears enormous loads, especially when driving on bad roads. There is a simple method to check its condition that does not require a lift. Open the hood, ask an assistant to actively turn the steering wheel from side to side, and put your hand on the coil of the shock absorber spring or on the support itself.
If a vibration is felt under the palm, radiating into the hand, or a characteristic crunching/grinding noise is heard, then the diagnosis is obvious: support bearing requires replacement. Ignoring this problem will lead to the fact that the shock absorber will no longer handle irregularities correctly and will begin to “bite,” which will accelerate the wear of the entire strut and rubber. In some cases, a damaged bearing may jam, and the steering wheel will simply stop turning in one direction.
It is important to note that on vehicles with McPherson Replacing the support bearing often requires completely disassembling the strut and compressing the spring. This is a dangerous procedure that requires special tools. Trying to remove a spring without ties can lead to injury, since the energy of a compressed spring is enormous.
When replacing support bearings, always replace them in pairs, even if the second one does not squeak yet. They have the same resource, and disassembling the unit again in a month will cost more.
Steering and rack problems
The steering rack is a complex mechanism that converts the rotation of the steering wheel into the movement of the wheels. A grinding noise when turning left may indicate wear in the gear-rack pair or wear of the sliding bushings. If water and dirt get into the mechanism through torn boots, the lubricant turns into an abrasive mess, which makes grinding sounds during operation.
It is also worth paying attention to steering shaft drive. This is an intermediate hinge connecting the steering column to the rack itself. Often it is jamming or drying out of the lubricant inside the crosspiece that gives an unpleasant metallic sound, especially in the extreme positions of the steering wheel. It is difficult to visually check the cardan; usually its condition is assessed by touch, rocking the shaft with your hand with the rack disconnected.
In hydraulic power steering (power steering), the pump can produce a grinding noise if there is little fluid in the system or it has lost its properties. However, the sound of the pump is more like a whine or hum. If you hear a grinding noise, check the tension of the power steering drive belt. A belt slipping over a pulley can produce a sound very similar to metal rubbing.
Why can the rail bite?
Often the reason lies not in the rack itself, but in the deformation of the subframe after an impact. The geometry is disrupted and the rack shaft begins to work misaligned, which causes rapid wear of the bushings and grinding noise.
Brake system as a source of noise
Brakes are one of the most common causes of grinding noise that is not directly related to the steering, but occurs during its operation. When you turn the steering wheel, the car body tilts and the load on the wheels is redistributed. If the brake disc has a strong wear (“step” along the edge) or is deformed (“slipped” disc), then when rolling, the pad may be pressed more tightly against the unevenness, producing a sound.
Particular attention should be paid brake shield. This is a thin metal plate that protects the disc from dirt. It bends easily. A small stone caught between the disc and the shield, or simply inactive movement through a deep puddle, is enough for the shield to bend towards the disc. When the wheel turns, the gap changes and the shield begins to rub against the rotating disk, creating a terrible grinding noise.
Also subject to wear brake pads to the metal base. Modern pads have special indicator plates that begin to creak in advance. But if the wear is critical, then the metal back of the pad rubs against the disc. This is not only noisy, but also dangerous, since braking efficiency drops to zero and the disc receives deep damage.
☑️ Brake diagnostics
Fault comparison table
To systematize the knowledge gained and help you quickly identify the source of the problem, we have compiled a table of the main symptoms. Please note that only a specialist can make an accurate diagnosis after examination on a lift, but this data will help narrow down the search.
| Malfunction | Character of sound | When it appears | Associated symptoms |
|---|---|---|---|
| Support bearing | Crunch, dry rattle | When turning the steering wheel in place or at low speed | Vibration on the shock absorber rod, hum when driving |
| CV joint (grenade) | Loud crunch, crackling | When turning the steering wheel while driving under load | Play in the drive, torn boot |
| Brake shield | Continuous metal grinding | Constantly when driving, worsens when cornering | Visual deformation of the shield, scratches on the disc |
| Steering rack | Knock, grinding noise in a pair of gears | When actively driving the steering wheel, on uneven surfaces | Steering play, power steering fluid leak, biting |
As can be seen from the table, grinding noise when turning the steering wheel to the left most often indicates problems with the support bearing of the left strut or the brake mechanism of the left wheel. However, the right side cannot be ruled out, since when turning left, the load is redistributed to the right wheel, and if there is a problem there (for example, a pressed pad), the sound may also change.
The main marker of a problem with the support bearing is an increase in sound precisely at the moment the steering wheel begins to rotate, when the car is stationary or moving very slowly.
Consequences of ignoring the problem
Many drivers mistakenly believe that if the car is moving and the steering wheel is turning, then the problem is not urgent. This is a dangerous misconception. Destruction of the support bearing leads to disruption of the shock absorber. The strut stops dampening vibrations, shocks are transmitted to the body and other suspension elements: silent blocks, ball joints, steering ends. The service life of these parts is reduced significantly.
In the worst case, if the bearing is completely destroyed or the steering rack is jammed, you can lose control of the car at high speed. Imagine the situation on the highway: you need to quickly move away from an obstacle, you turn the steering wheel, but it bites or the wheel is blocked due to problems with the brake caliper. This is a direct threat to life.
⚠️ Attention: If the grinding noise is accompanied by vibration in the steering wheel or pounding in the brake pedal, stop using the vehicle immediately. Further movement is only possible to the nearest service station using a tow truck or tow truck.
In addition, the constant grinding of the brake elements leads to overheating of the disc. The metal changes its structure (is released), blue spots (“tarnish colors”) appear, and the disk moves in a “figure eight.” It is no longer possible to restore such a disc by grooving, only replacement.
Methods of elimination and prevention
Eliminating the grinding noise depends on the identified cause. If the problem is in the support bearing, the support is replaced. On many modern cars, the supports are sold assembled with a bearing, but there are also separate elements. During assembly, it is important to correctly install the bearing and not overtighten the rod nut, so as not to damage the new unit.
If there are problems with the brake shield, it is often simply bent back with a screwdriver, restoring the gap. If the shield is torn or severely deformed, it is better to replace it, since the thin metal can bend again and jam the wheel. Brake discs with deep grooves must be replaced; regrooving is permissible only if the remaining thickness allows this to be done according to factory specifications.
Is it possible to lubricate the support bearing?
In most modern bearings, the bearing is sealed and cannot be serviced. Trying to drill the housing and fill it with grease is a temporary measure that will only delay the replacement by a couple of weeks, since the seal has already been compromised.
To prevent the occurrence of such problems, it is recommended to regularly undergo diagnostics of the chassis. Particular attention should be paid to the condition of the CV joint boots and steering rack. An intact boot is the key to a long life of the unit. Also avoid sudden starts with the steering wheel turned all the way - this is a killer load for the transmission and suspension.
⚠️ Attention: Never hold the steering wheel in the extreme position for more than 5 seconds while the engine is running (especially with power steering). This creates excess pressure in the system, heats the fluid and accelerates wear on the pump and rack.
Use high-quality lubricants during maintenance. The caliper guides require a special high-temperature lubricant that does not corrode the rubber seals. For hinges - thick lithium or molybdenum compounds. The use of unsuitable lubricants (for example, conventional Litol-24 in high-temperature components) leads to their drying out and coking, which causes grinding noise.
The quality of spare parts is critical. Cheap Chinese support bearings can begin to creak after 2-3 thousand kilometers.
Frequently asked questions (FAQ)
Could the grinding noise be related to the engine oil level?
No, the engine oil level does not affect the sounds in the suspension when turning the steering wheel. However, if the grinding noise comes from under the hood and depends on engine speed rather than wheel position, it may be a problem with the attachment (alternator, pump, casters).
Why does the grinding noise get worse in cold weather?
In cold weather, the lubricant in components (bearings, hinges) thickens and loses its properties, and frictional resistance increases. In addition, the metal elements are compressed and the gaps are reduced, which can lead to contacts that are inaudible in warm weather. Rubber seals also harden and may make squeaking sounds.
Is it dangerous to drive if the grinding noise is quiet and appears rarely?
Yes, it's dangerous. Any mechanical damage tends to progress. A quiet grinding noise today can turn into a loud crunch in a week, and in a month into a wheel jam. Repairing at an early stage is always cheaper and safer than replacing the entire assembly after an accident.
How to distinguish the sound of a CV joint from the sound of a wheel bearing?
The CV joint usually crunches when turning the wheels. in motion under load (during acceleration). The hub bearing most often hums or howls, and this hum intensifies as the speed increases, and when turning the steering wheel it can change its tone (diminishing or intensifying depending on which wheel the weight is transferred to).
Do I need to change the stabilizer links when replacing the support bearings?
It is not necessary, but it is advisable to diagnose them. Often when disassembling the front suspension, play is discovered in the stabilizer struts. Since the labor costs for replacing them at this moment are minimal (access is open), it makes sense to replace them preventively if the car's mileage is high.