Self-diagnosis and repair of the running gear of the car

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

The chassis is an integral part of any car. It is she who provides the connection between the car body and the wheels. This property is realized thanks to the guides and elastic elements. Modern automakers are paying more and more attention to the comfort and reliability of the suspension. However, as experience shows, no matter how reliable it may be, on our roads the chassis breaks very quickly. Faults can be very different. But how to diagnose, maintain and repair the running gear of a car? We will consider this in our today's article.

What is diagnosed during MOT?

Usually, during TO-1, the following elements are checked:

• Protective rubber boots for ball joints.
• The supports themselves for backlash.
• Wheels for imbalance.
• On older cars, clearance in the king pins.

When TO-2 checks the status:

• Front wheel alignment.
• Knuckle.
• Spring fingers and stepladders (if any are provided by the designpendants).
• Rubber sway bar.
• Rubber grommets.
• Shock absorber elasticity.

In case of undetected malfunctions, the car's running gear is being repaired.

External inspection

To make an independent diagnosis, at the first stage you need to inspect all the elements of the suspension externally. To do this, it is desirable to have a viewing hole (or better - a lift). In extreme cases, you can raise the car with a jack. First of all, the suspension elements must be inspected for cracks. They shouldn't be. Also, often with serious collisions with pits, the suspension arms bend. Because of this, it is sometimes impossible to set the wheel alignment, as a result, rubber suffers greatly.

It is worth paying attention to the brake hoses. They primarily affect safety. Hoses are usually two-layer, but if the outer one is damaged, it is already worth thinking about replacing it. Also, these elements change if there are leaks of brake fluid.

What can be checked in the front suspension?

First of all, attention is paid to leverage. Now most cars have independent suspension with MacPherson struts. Over time, the silent blocks of the levers wear out and play at the junction of the bushings. This can be checked with a pry bar by placing it in a certain slot and moving the lever to the side. If it is loose and "walks", you need to repair the chassis of the car. Usually silent blocks change separately from levers. For this rubber-metalproducts are pressed out from the previously unscrewed lever and new ones are pressed in their place. Ball bearings are also subject to backlash. They also change if the rubber boot is damaged on them. Even if no backlash is found, but the cover is torn, this is a reason to repair the chassis of the car. To do this, the car wheel is hung out and the ball joint is unscrewed from the mounts. They can turn sour, so keep a liquid lubricant handy at all times, as well as a metal brush to scrape off the dirt.

About trucks

On trucks, the front suspension is somewhat different. It uses a pivot beam with semi-elliptical springs. Repair of the undercarriage of a truck is needed if the wheel in the suspended state begins to move from side to side. This symptom can indicate several problems at once:

• Wear wheel bearing.
• Problems with steering tips.
• Problems with the kingpin.

About the kingpins

This malfunction is one of the most serious, although it is diagnosed infrequently. The kingpin is developed over time and the wheel begins to play. This problem is accompanied by uneven tire burning and poor handling of the car itself.

You can replace the kingpin without removing the beam. But, as a rule, such an operation is entrusted to professionals. It is often not possible to knock out an old kingpin without heating. By the way, it changes in pairs, even if the neighboring one is in good condition.

Rear suspension

If we talk about cars, there may be a semi-dependent beam or a multi-link. In principle, the repair of the running gear of the car is not required so often. Usually the rear suspension begins to require attention after 100-150 thousand kilometers. If we talk about the beam, it is almost eternal. Silent blocks go more than 200 thousand. But in case of a malfunction, they are diagnosed very easily - a backlash appears. The same applies to the multi-link scheme. The levers are checked with a mount, as well as from the front. If there is play (it is advisable to check this on a fully suspended wheel), repair of the chassis is required. VAZ cars of classic models have "Panara" traction at the back. It can fall off the body over time. But it's easy to check her condition. If it does not move away from the body, and there are no cracks at the attachment points, then everything is in order with it.

Bearings

It is worth talking about them separately. If you touch on cars with MacPherson suspension, it is worth including thrust bearings in addition to wheel bearings. They are installed at the top of the rack and are located under the hood, on the so-called cups. It is on them that the entire shock load is assigned. If they fail, the driver hears a characteristic clicking sound when turning left or right. The support bearing is changed separately. Finding it is easy - it is hidden behind a plastic or metal cover.

Also, repair and maintenance of the running gear of the car include inspection and replacement of wheel bearings. You can recognize their malfunction by hanging the wheel, rotating the disk alongor counterclockwise. If a characteristic rustle and hum is noticed, then the element has become unusable. Also, when the bearing is completely broken, the wheel will play if you grab it with both hands.

How is the car undercarriage repaired in this case? To replace the wheel bearing, you will need a puller with two or three “paws”, as well as a vice. The procedure takes place in several stages:

• The hub nut is loosened from the part where the failure was diagnosed.
• Dismantling the wheel.
• If this is a rear axle, the drum brake cover is disassembled (the pads themselves and the cable remain in place).
• The hub is removed along with the bearing.
• The old element is pulled out with a puller.
• A new one is installed in its place. The seat is preliminarily cleaned of dirt and lubricated with Litol.
• Assembly in reverse order.

When repairing the chassis, it is important to observe two points:

• Insert the new bearing evenly into the hub. To eliminate distortions, you can use the clip of the old one (it perfectly follows the contours), pressing the element through it.
• Do not overtighten the hub nut. The tightening force is regulated individually and is in the instruction manual. As a result, the wheel should rotate freely, but at the same time there should be no play.

Shock absorbers

Performing diagnostics and repair of the running gear of the car,It is worth paying attention to the shock absorbers. A characteristic sign of a breakdown is oil streaks that come from the cylinders along the outer casing. But it may not always be visible. There is another way to diagnose shock absorbers. You need to swing the front, and then the back of the car. The machine should stop jumping for the second time after the swing. If she continues to "nod", then the shock absorbers are not doing their job.

You can also check them on the go. After accelerating to 60-80 kilometers per hour on a flat and deserted road, brake. If the car strongly "pecks" down, and after stopping it sways a few more times, it means that the front shock absorbers have become unusable. On serviceable elements, no swaying should be observed. Do not ignore repairs. The car on faulty shock absorbers will inexorably stray from the trajectory and hold the road uncertainly. At one point, this can lead to loss of control and an accident.

Signs indicating breakdowns

During the movement, the driver may encounter such a problem as pulling the car to the side. You have to constantly taxi, especially at speed. This may indicate several malfunctions:

• Damage to upper shock absorber mount (typical for MacPherson suspension).
• Violation of the steering wheel toe angle setting.
• Deformation of the suspension arm and cross stabilizer.

The next factor thatindicates an upcoming repair, is the rocking of the body when cornering and braking. This may be a malfunction of the bushings or the anti-roll bar itself. Also, similar signs are observed when the shock absorber breaks down.

Vibration when braking indicates wear on the brake discs. Knocking during movement is a consequence of a malfunction of the rubber-metal suspension mounting elements. Also, knocks occur when the spring breaks. But, as a rule, this malfunction is diagnosed before anyone else - after all, the machine will be tilted to one side down.

The so-called suspension breakdown says:

• Suspension arm malfunctions.
• Reducing the stiffness of the spring and its subsidence.
• Wear of silent blocks and shock absorbers.

Repair of the running gear of the car in SEAD

Many car owners prefer not to interfere in diagnostics and self-repair. This is especially true for expensive cars, where the running gear is quite complicated. Today there are a lot of services offering professional diagnostics and suspension repairs on cars of different brands.

One of these is the Pekto-M car service, located at 1st Veshnyakovsky pr., 2, Moscow. The service has positive customer reviews and deals not only with the running gear. Repair of a car engine, in particular, fuel equipment is one of the main areas of this service.

Conclusion

So, we found out the intricacies of car suspension diagnostics and repair options. Howyou see, among the main signs in most cases are increased knocks, backlash and noise during movement. A serviceable suspension (whatever its design) should silently work out all the bumps or, at least, not make characteristic noises and vibrations. If any were found, this is an occasion for a detailed diagnosis of the chassis. Performing this operation on your own, it is worth acquiring a viewing hole. No special tools are required - only skillful hands and a pry bar to check the condition of the levers and ball joints.