Car chassis repair Riga-Latvia

What is the undercarriage of a car

Suspensions, front and rear, are part of the chassis of the vehicle, which is its load-bearing part.

The suspension connects the body and wheels, ensures maximum safety while driving, softens the impact of the wheels on the road and dampens vibrations of the body itself.

Suspensions are dependent, when the movement of one wheel depends on the movement of the other, and independent, when each wheel is attached to the body separately.

The suspension is an intermediate link between the body and the road and should provide maximum safety while driving. Therefore, precise kinematics, ease of steering wheels and rolling stiffness of radial tires are required.

The suspension transmits to the body the force that occurs when the wheel contacts the road, so the suspension must be strong and durable.

Any suspension consists of:

  • elastic element;
  • shock absorber;
  • a guiding device to ensure the vertical movement of the wheels;
  • anti-roll bar.

Undercarriage Malfunction Symptoms

It is recommended that you immediately contact a specialist to diagnose the suspension if you find:

  • Knocking in the suspension while driving;
  • Grinding, knocking when crossing road defects;
  • Extraneous noise from the front or rear when cornering;
  • Large backlash in the steering wheel;
  • Situations when the car is pulled to the side;
  • Vibrations with recoil to the steering wheel and body;
  • Uneven wear on car tires;
  • Fluid leaks.

Diagnostics of various elements of the undercarriage

What does the repair of a running car in a car service consist of –

Visual inspection and diagnostics on a special stand

Determination of the scope of work based on the detected faults

· Trouble-shooting

Diagnostics can be visual and poster. If visual diagnostics determines the degree of wear, for example, or the presence of cracks, then modern electronic stands are used to check the alignment angles of the steered wheels, which must be carried out after the suspension has been repaired.

The main advantages of these stands are high manufacturability, good metrological characteristics, the ability to output information to digital and analog indicators, to the display screen.

Computer diagnostics of the car chassis at a specialized stand allows you to detect all deviations in the operation of the chassis. The machine is subjected to loads that simulate road traffic. At this time, special sensors record the operation of the chassis. Based on computer diagnostics, you can give the most accurate answer to the technical condition of the suspension.

During diagnostics, the specialist pays attention to the following elements of the chassis of your car:

– ball bearings;

– silent blocks and suspension arms;

shock absorber struts;

– springs and suspension springs;

– rods and tips of the steering system;

– wheel hub bearings;

– crosspieces and hinges of equal angular velocities (SHRUS);

– anti-roll bars;

Unfortunately, many motorists, trying to save some money, try to independently determine the cause of the extraneous noise.

Diagnostics, as well as the necessary repairs, should only be performed by specialized service workers using the appropriate equipment using the most modern techniques in this area. This facilitates early identification of faults and guarantees subsequent high-quality repairs.

If unpleasant extraneous sounds occur when the car is moving in the area of the front suspension, you should immediately go to the nearest car service for diagnostics.

Checking the technical condition of the undercarriage and repair

Front suspension

In modern vehicles, front suspension maintenance begins with an inspection of its condition.

Checking the technical condition of the front suspension is carried out when signs of its malfunction appear and for preventive purposes, since traffic safety depends on the serviceability of the suspension.

As a rule, the main cause of knocking in the front suspension is wear of ball joints, hub bearings, steering ends or shock absorber struts

In the course of diagnosing front suspension assemblies, it is necessary to pay some attention to the condition of the shock absorber struts.

Replacing shock absorbers – a rather complex technical operation, the required quality of which can be achieved only when this work is performed by professionals.

Diagnostics and replacement of shock absorbers

Shock absorbers are necessary to suppress vibrations, making the movement of the machine more comfortable. Without them, the car will swing heavily while driving over bumps.

Damage symptoms of a shock absorber:

  • Constant knocking when moving irregularities;
  • Vibration, auto throws from side to side;
  • Constant rocking of the car body after driving through irregularities.

Operating a car with faulty shock absorbers is dangerous:

  • Vehicle handling deteriorates due to rocking;
  • If the shock absorber gets stuck, the suspension will become very stiff.

You can check the performance of the shock absorbers by swinging or pressure on the car body, if the body immediately dampens vibrations, then most likely everything is in order. Also, by visual inspection, if there are oil leaks, then this indicates a malfunction of the unit.

Do-it-yourself chassis repair, namely the replacement of suspension shock absorbers, we do not recommend performing. The replacement process does not include anything complicated, however, if the replacement is incorrect, the likelihood of an imbalance in the car increases, which will affect when driving at high speeds, and can lead to an emergency.

The inspection also checks:

  • suspension elements in order to detect damage, wear of elastic elements: rubber buffers, bushings, silent blocks (the so-called rubber-metal hinges);
  • the possibility of fluid leakage from shock absorbers and shock absorbers;
  • wear of rubber-metal hinges, it is determined visually by the presence of bulging rubber;
  • checking suspension fasteners;
  • checking the settlement of the front suspension springs, it is carried out after the car is installed on a flat horizontal platform with its full load;
  • the uneven settlement of the springs is determined by the roll of the body.

In the presence of deformations and cracks on the suspension elements, damage to the protective covers of the ball joints, increased wear of the elastic elements, they must be repaired or replaced.

Front suspension repair includes the following steps:

  • checking the technical condition of the front suspension;
  • disassembly, replacement and repair of parts;
  • assembly and adjustment of the front wheel alignment angles.

Rear suspension consists of a transverse bridge, telescopic shock absorbers and coil springs.

Checking the technical condition of the rear suspension includes: checking the suspension, checking the performance of the shock absorbers, checking the settling of the springs or springs. This is done in the same manner as checking the front suspension.

On front wheel drive vehicles, camber and rear toe are also checked.

Rear suspension parts repair includes:

  • repair of shock absorbers (performed in the same way as repair of shock absorbers of the front suspension);
  • replacement of silent blocks;
  • replacement of levers and rods;
  • repair of springs.


The main malfunctions of the springs are the wear of the parts of the hinge joints, the breakage of individual sheets, the subsidence of the spring. creak. A squeak appears when the anti-squeak gaskets and washers are worn out and are eliminated by replacing them. And when the springs sag, they are replaced with new ones, even if one sags, to avoid body roll.

Diagnostics and replacement of levers

The arm is the main bearing element of the machine’s suspension. The lever acts as a stabilizing element. If there is a violation of the suspension geometry, then the chassis needs to be repaired.

Signs of a malfunctioning suspension arms:

  • Knocking while driving;
  • Increased stopping distance;
  • Crunch or hum when turning;
  • Poor machine stability;
  • Large roll when cornering;
  • Uneven tire wear;
  • Quick wear of silent blocks.

The silent blocks are diagnosed in the same way as the ball joint, if there is a backlash, replacement is necessary. It is worth noting that the silent blocks do not change on all levers, and change entirely with the lever. After replacing levers or silent blocks, it is imperative to check and set the correct wheel alignment angles.

Diagnostics and replacement of the ball joint

Replacing ball joints is an event that must be carried out in a timely manner. Ball joints break most often during movement, and at the most unnecessary moment. We can say that this is the most vulnerable part of the suspension. Therefore, it is so important to diagnose this unit in order to identify problems with the ball joint in time.

Signs of a ball joint malfunction:

  • When crossing tram tracks, artificial irregularities, defects in the road surface at low speed, knocks are heard in the front suspension;
  • The front wheel is loose (swinging). In such a situation, it is dangerous to postpone the diagnosis and replacement of the ball joint, there is a high risk of an emergency;
  • Squeak when turning the steering wheel;
  • Uneven tire wear on the front and rear axles.

Diagnostics and replacement of wheel bearings

This is an important element that performs the function of wheel rotation. From high mileage or improper operation, this unit may fail. Replacing the hub bearing is a mandatory procedure, ignoring the breakdown can lead to a serious accident.

Signs of a defective hub bearing:

  1. Crunching while driving. This is the first symptom, it can be heard well in the cabin, in which case it is already necessary to go to the service station.
  2. The presence of vibration in the steering wheel and on the car body. This indicates a strong wear of the bearing; in this case, it cannot be pulled with replacement.
  3. The car is pulled to the side. Symptoms are similar as with improper wheel alignment.

Replacing a hub bearing is a technically complex undertaking that requires experience, professionalism and special tools. Incorrect mounting or dismounting can lead to serious malfunctions.