Suspension or steering
A knock on small bumps does not always indicate a breakdown in the suspension. Similar sounds may come from the steering. You need to check the suspension and steering rack.
When this mechanism is faulty, vibration on the steering wheel is noticeable when driving on uneven roads. A large gap appears between the rack and gear, increasing over time, and vibration also increases. To get rid of the problem, you need to tighten the rail.
The problem may be related to the bushings on the tie rods. The parts need to be swung individually with a pry bar. If there is significant play, the element should be replaced.
If after tightening the rack and replacing the bushings the problem remains, you need to check the steering joint. For diagnostics, 2 people are needed: one must fix the hinge, body and pin, and the other must turn the steering wheel sharply at a small angle. If there is play, it will become clear that the mechanism requires replacement.
It is worth checking the steering rack ends. A sign of wear - a characteristic sound appears when the steering wheel is rotated while driving at a small angle, play is noticeable. The tips cannot be repaired; only replacement will help.
If the knock remains after the work, a full suspension diagnosis is required.
Front suspension diagram
Troubleshooting in the rack
Basically, the strut can make a knock and transmit impacts from uneven roads only when the entire structure is severely worn. Moreover, this element of the car suffers the most when the front pair of wheels falls into a deep hole - the rebound strut does not work, but the spring undergoes a sharp straightening. As a result, the wheel will go sharply down, stretching the spring to the maximum possible length. Thus, it turns out to be 2 hits - the racks against the support and the racks with the bottom of the pit.
Checking the functionality of the support pillar is carried out in a standard way - the vehicle is swung vertically or a partner presses forcefully on the central part of the hood. If the rack is in good condition, the body of the machine should return to its original state once without sharp straightening.
If the case falls sharply, you will hear a dull thud. This indicates a malfunction of the element due to a loose lock nut, which makes noise inside the support post itself. Repair of the rack should only be carried out at a car service center, since special equipment will be used to secure all elements in a high-quality manner.
If a knock occurs on small bumps due to the strut, the car sways strongly when moving and loses control. This may result in an accident on uneven roads.
Also, problems may lie not in the strut itself, but in the shock absorbers. A malfunction of the shock absorber system is primarily due to improper treatment with oil. Drivers often pour an oil solution with incorrect viscosity characteristics inside. This value is affected not only by the purchased oil, but also by the ambient temperature at which the solution is poured. Too low a temperature does not allow the oil fluidity to increase to the required value.
We recommend: What is body straightening and how to do it yourself
Stabilizer bushings
It is difficult to determine the breakdown of elements by sound. In order not to change the part, you need to check the bushing by hand. This can be done by a mechanic at a service station.
The malfunction can easily be confused with failed silent blocks. The difference is that if the bushings are installed on a subframe, the driver will feel vibration in his legs while driving.
Attention! It is impossible to check and replace the bushings on a lift; you need an inspection hole or platform so that the load is applied to the wheels.
If the parts are faulty, vibration will occur on any bumps.
Front suspension installed with defects
A possible reason for the appearance of knocking on bumps may be the occurrence of defects in the lever system. At the same time, you will notice changes for the worse in the car's handling. The only culprit in this situation is a set of silent blocks.
To check for problems, you need to diagnose the levers. You can do it yourself using a regular mount. To do this, use the pry bar as an extended arm to create a counterweight and bend each of the arms in different directions. If you find significant play in the structure (discrepancy of more than 5-7 cm), then it is worth carrying out maintenance on the suspension.
If the machine has a collapsible structure, then you only need to replace the old set of silent blocks with a new one. The replacement process is as follows:
- First you need to dismantle the levers;
- Then the stage of pressing out the set of silent blocks from the fixed holes occurs. To do this, use a special mandrel;
- Install a new set of silent blocks, having previously generously lubricated each of them to reduce friction during operation. Also, do not forget to clean the mounting surface of the suspension from all dust and dirt before installation.
Front suspension
Tip: If the suspension was supplied with defects from the manufacturer, then in case of an unexpired warranty, you can contact the dealer, and he will be obliged to replace the defective parts free of charge. Also be sure to check the rear axle of the VAZ-2107.
Stabilizer's pole
The part is used to attach the stabilizer to the suspension. If there is a malfunction, the chassis begins to knock loudly. Knocks can be accompanied by strong car rolls when cornering, during acceleration and braking; it is necessary to constantly steer.
The breakdown occurs due to the anthers becoming unusable, moisture and dirt getting into the mechanism, and wear occurs.
To check the stabilizer links, you need to rock a stationary car. If this happens easily and with a knock, the part is faulty.
Another way to check is to turn the wheel and pull the rods. If there are gaps, it’s time to change the racks. Work should be done on a pit or platform for convenience.
It is important to check the anthers. If the mechanisms are torn, and there is moisture inside and there is no lubrication, it’s time to change the rack.
It is recommended to purchase a new part and replace it.
Consequences
It is highly undesirable to leave suspension knocks unattended. Some of them are relatively harmless, such as play in the stabilizer links, but most lead to destruction of the suspension guide vane.
This is fraught with separation of one of the hinges and the occurrence of an uncontrolled deviation of the plane of rotation of the wheel. The car loses stability and goes out of the driver's control.
In order to avoid such incidents, diagnostics of the suspension condition must be carried out during each routine maintenance of the vehicle.
It consists of a visual inspection on the lift, checking all hinges, shock absorbers, springs and the presence of fatigue cracks on parts. Ends with a control trip in the presence of a master.
Checking silent blocks
Car suspensions contain levers whose structure contains silent blocks. Elements are necessary for attaching shock absorbers.
Over time, the part wears out and cannot fulfill its role. “Rolling” appears and the car handles worse. When the silent block becomes unusable, play occurs.
To check the part you need a jack and a pry bar. Necessary:
- Raise the car so that the wheel is hanging out.
- Using a pry bar, loosen the suspension arms, checking for play.
If there is a gap and is accompanied by knocking noises, the part is faulty and needs replacement. It is necessary to check both silent blocks.
Attention! The parts wear out evenly, it is recommended to change them together, even if one does not play.
The process is simple: you need to remove the levers and dismantle the silent blocks. You will need a special tool.
Spherical bearing
The front suspension of passenger cars has 2 ball joints - one for each wheel. signs of malfunction:
- The steering wheel turns harder.
- Knocks are heard in the front suspension when driving.
- Controllability deteriorates, the wheels “float”.
- The rubber tread wears off intensively.
- Wheel alignment is not displayed.
You can determine if the ball joints are faulty by diagnostics: hang the car wheel with a jack or on a lift, hold down the brake pedal, and turn the wheel from the outside. The procedure must be carried out together.
If, during a sharp turn, play appears, accompanied by a knocking sound, an urgent replacement of the ball joints is necessary. The anthers should be checked. The parts must be intact, otherwise they will become unusable.
Wheel bearings
The initial stage of breakdown is accompanied by a hum. To make sure that the wheel bearings are faulty, you need to accelerate the car to 50 km/h and perform the “snake” exercise, turning the steering wheel slightly. If you hear a hum, the parts are broken. On which side the sound is stronger, on that side the part is worn out more.
Diagnostics is possible using special equipment, or you can perform the procedure yourself. Necessary:
- Raise the front axle of the car.
- Grab the wheel from above and below with your hands.
- Try tilting.
If the bearing is good, the wheel will be fixed and will not move. The presence of play means the part has become unusable. The problem may arise from the steering rack.
Attention! For vehicles with a front drive axle, the wheels are checked vertically and horizontally.
You cannot continue operating the machine with faulty bearings. The breakdown must be repaired, otherwise the mechanism may suddenly jam.
Signs of bad wheel bearings
Balloons are no joke
The cause of knocks and squeaks is often wear and tear on the ball joints. This is a very important part in the form of a hinge that connects the wheel hub to the suspension arm. True, ball joints usually knock only on rear-wheel drive cars with a simple suspension. On front-wheel drive vehicles, the malfunction manifests itself in the form of a squeaking sound. The exception is cases when wear reaches a critical value, i.e. the hinge begins to simply dangle in the body.
To verify that the ball joint is faulty, you need to hang the wheel, press the brake pedal and try to turn the wheel left and right. If there is play and knocking, then the ball needs to be changed. It must be said that in some cars, such as the Lada Granta or VAZ 2110, the ball joint is bolted on, so replacing it is not difficult. But sometimes there are supports that are pressed into the lever (Mercedes CLS W219 or SsangYong Rexton). Accordingly, they are replaced along with the lever, even if it is still in good condition.
If no play is detected, you need to check the condition of the boot. The fact is that often the cause of noise in ball joints is dirt getting under the joint. Therefore, you need to add lubricant to the hinge and replace the boot.
A rupture of the ball joint (tearing out the hinge from the body) can cause an accident, since in this case the wheel turns out and the car falls on the asphalt. Therefore, when the first signs of wear appear, it must be changed.
Brake problems
If a knocking noise occurs when you press or lower the brake pedal, there is a problem with the ABS (anti-lock braking system). This nuance arises after repair work was performed incorrectly.
Brake problems:
- Damage to the seats for the caliper guides, which is loose and vibrates. Parts need to be replaced.
- Caliper piston jamming. The element hits the pads sharply, causing a knocking sound. The piston changes.
- Brake disc guidance. Due to high temperatures, the part may change shape and bend. The pads begin to wear unevenly. You need to check the disk on special equipment in order to replace it in time.
- The pad retainer has come off and will hit the drum, creating a knocking sound. The part needs to be installed in place and the cause of the jumping off must be determined.
The problem is related to a malfunction in the ABS. It is enough to remove the corresponding fuse from the block. If after carrying out the actions the knocking stops, the ABS is faulty. Specialists can fix the problem; there is no need to try to fix it yourself.
Engine support cushions
The pillows contain rubber elements that wear out over time. Because of this, the car rattles when driving.
You need to open the hood and start the engine. Strong vibration indicates that the parts have become unusable. If the engine shakes or tilts more when you press the gas, it's time to change the elements.
You can check the integrity of the pillows yourself without visually. You need to try to shake the power unit. If the action can be performed without effort, it’s time to change the pillows.
You should not ignore such a breakdown; due to the force of vibration, various components are destroyed. When the part becomes unusable, the motor breaks off its mounts, and serious repairs will be required.
You can change the pillows yourself. Without work experience, you should contact the experts.
