From A to Z: everything about dismantling and replacing car thresholds

What are the defects?

According to the type of attachment to the supporting body, the thresholds are classified into removable, which are installed on the body with bolts, and non-removable. The elements are welded to the sidewall and provide the car structure with the necessary rigidity and reinforcement. Regardless of the type of installation, the elements suffer the same damage.

1. Dents. Defects are formed from impacts with gravel, careless parking, or as a result of a minor accident. Mechanical damage from gravel damages the outer part of the underbody, wheel arches, and side members.
2. Scratches, chips. The outer part is damaged. The defect does not affect driving safety; the appearance of the car suffers.
3. Corrosion. Rust occurs due to natural wear and tear of the metal and due to improper processing or lack of anti-gravel protection. The degree of wear affects driving safety. If the non-removable threshold, as part of the power element of the body, rots, the overall geometry of the structure changes, the main components and assemblies are distorted: the engine and transmission elements.

Depending on the defect, the repair method is selected: welding, pulling out dents, straightening using spot welding, or sealing holes with adhesive.

Repairing a jammed car sill without painting

Repairing thresholds without subsequent painting is a rather rare type of work. If the element is not removable and there is a small dent, but there are no sharp edges, then you can use suction cups. The complexity of the method lies in the fact that the tool is difficult to install on the part; it is necessary to make a cut.

It is easier to use a reverse hammer and a spot welder to draw out the metal. Restoration of body parts without painting is carried out at specialized service stations using tools; the PDR method is used for straightening dents on wings, doors, bumpers, and roofs. The cost of work is from 3,000 rubles.

When the threshold is removable, you can remove the dent without painting using straightening hammers and polish, if the dent is shallow and there is no break in the paint layer.

Plastic thresholds

The VAZ 2107 is a rather old car, which is no longer in production at the moment. Nevertheless, the “seven” is still popular in our country to this day, and many drivers want to somehow make their car stand out from the crowd. Very often, a so-called body kit is used for this, which includes plastic sills (sometimes these parts are called sill moldings, sometimes plastic overlays, it’s all the same thing). The function of plastic thresholds is purely decorative; these details do not solve any practical problem.

A set of factory plastic thresholds for the VAZ 2107, which can be purchased at any tuning spare parts store

Particularly advanced drivers make plastic thresholds themselves. But for this you need to have special equipment for working with polymer material, plus you need to get the industrial polymer itself somewhere, which is not so easy. Therefore, car owners take the easier route and simply buy plastic thresholds; fortunately, there is no shortage of them now. But when choosing pads in a store, you should consider several nuances:

• In addition to purely aesthetic qualities, attention must also be paid to the mechanical properties of the thresholds. The linings purchased should not be too hard, because such products quickly crack, especially if the machine is operated in cold regions of the country. For this reason, fiberglass overlays should be abandoned;
• The best choice for the “seven” would be plastic linings with the addition of synthetic resins. These linings are flexible and do not crack due to temperature changes or exposure to road chemicals.

Repairing a rotten car threshold

If corrosive wear of more than 40% is observed, it is recommended to use partial or complete replacement of the part. Re-welding of thresholds is more often used on non-removable elements; removable fairings are replaced in 80% of cases with new ones. The cost of removable parts does not exceed the cost of repair. Depending on the extent of the damage, drivers choose one of the following options:

1. Partial replacement of a rotten section without replacing the amplifier. The rotten part is cut out or knocked out, and a metal patch is installed.
2. Complete element replacement. It is used if corrosion has destroyed the threshold amplifier, electric welding is used.
3. Redecoration with fiberglass. Used only as a temporary measure. More often than not, unscrupulous owners hide rotten body parts in such a cheap way before selling them.

What is the price for body repair of car sills in our auto repair shop (metro station Yugo-Zapadnaya)?

The cost of restoring car sills depends on many factors. First of all, of course, the degree of deformation is taken into account. So, in some situations there is no need to level the part and no pile work is involved. In other circumstances, a full range of body repairs is needed.

The cost of the vehicle itself is also taken into account: in some situations, for overly expensive models, the price may be increased, since the employee needs to take many points into account. To find out the cost of repair, you just need to send a photo of the faulty thresholds, and we can quickly determine the approximate cost of repair.

Stages of work for complete replacement

Replacing a threshold is a labor-intensive and complex process, but this type of repair remains the most productive and reliable. During the repair process, all main parts of the body are checked: the bottom, fenders, wheel arches. If the elements have traces of rust, dents, etc., then drivers can immediately carry out reconstruction and preserve the body for at least another 5 years. A complete replacement of the threshold takes place in stages:

• interior dismantling;
• cutting out an old threshold;
• preparation of the seat;
• welding of a new threshold;
• painting.

Repair technology

Fixed thresholds are repaired in two ways: with or without welding. The method of sealing holes in the outer cover of an element with a soldering iron is not recommended either by experienced drivers or service station technicians. After soldering, the process of electrochemical corrosion begins on the metal, as the structure of the metal of the patch and the base is destroyed. You can solder the threshold in exceptional cases, not forgetting that this is a temporary measure that will require a complete reinstallation of the part in 3-6 months.

It is also recommended to use fiberglass to seal through individual corrosion plaques in exceptional cases. This is a short-lived cosmetic type of repair that does not provide reliable structural rigidity. Repairing car thresholds with epoxy glue and fiberglass in steps:

1. Use a grinder to cut off the old paint and clean the area of ​​corrosion.
2. Treat the surface with a rust converter and sand it with sandpaper.
3. Dilute the epoxy resin, be sure to add aluminum or copper powder to the glue.
4. Cut 3-7 patches from fiberglass with an area slightly larger than the hole to be repaired.
5. Apply epoxy slurry to the surface and apply a patch.
6. Coat the repair area and apply fiberglass in several layers.
7. Roll with a rubber roller, remove air and excess glue.

Epoxy glue dries in 24-36 hours. After this, it should be cleaned with medium abrasive sandpaper, primed and painted.

The best method of repair remains welding; how to digest thresholds depends on the degree of damage to the element. It is recommended to use electric welding using a carbon dioxide semiautomatic device or an inverter. Gas welding using electrodes is a rather complex type of work, since it is necessary to have extensive experience and practical skills in order not to burn through the metal and lay a high-quality seam.

What can miscalculations in the process of body repair of car thresholds lead to?

Body repair is called a rather difficult procedure. Malfunctions especially often occur when painting a car. Any mistake can lead to all sorts of problems, the removal of which will take a lot of time, so it is better to immediately contact experienced professionals. The most common troubles are the following:

1. Grain.
   The rough granular structure of a painted surface can begin in a number of cases: dust has gotten onto the coating during the painting or drying process, there are solid particles in the paint, or the paint has been sprayed from a very long distance.
2. Peeling of varnish.
   Usually this happens due to incompatibility of the varnish and the undercoat, poor rust removal, application of varnish directly to the metal, and much more.
3. Craters.
   This problem occurs when paint is applied in excessively humid conditions. In specialized technical centers, painting booths are provided for this purpose, which eliminate such errors.
4. Dullness.
   This happens when there is high humidity or in circumstances where the car is not cleaned too often.
5. Leaks.
   This usually happens because the paint is too liquid: it quickly rolls down the body coating. In addition, similar defects occur when painting a car in the cold.

It should be noted that the defects described above can be avoided if you contact the “correct” auto repair shops. Visit us and we will implement everything you need as quickly as possible and at a reasonable cost.

How to digest rapids

Do-it-yourself welding of car thresholds takes place according to the following algorithm:

1. An inverter is the simplest method of semi-automatic welding; it is recommended not to buy the device, but to rent it.
2. Check the garage electrical network for load capacity and stable voltage supply without surges.
3. Charge the welding machine with wire, connect the phases, check the electric welding for functionality.
4. Before welding work, the threshold is grabbed onto points and the geometry of the body and the tightness of the door are checked.
5. It is recommended to weld not with a continuous seam, but in increments: 2 cm seam, 5 cm gap.
6. They start cooking from the central counter, first under the front door, then under the back.
7. After welding, the seam must be carefully cleaned without completely removing the beads, this reduces the rigidity of the structure.

Replacement process

Let's look at how to replace thresholds on a VAZ with your own hands. Before cutting or welding anything, you need to remove all the doors, and then pull out the threshold; it is located under the door seals. Now you need to remove the seals to make it easier to work with the thresholds, and also leave the rubber bands intact.

Next you need to cut off the rotten parts of the thresholds, but this should be done starting from the places at the front doors, then at the rear, and only at the very end in the center. This is done so as not to damage the central pillar.

We remove all rotten places using a grinder or a thin drill; the back of the threshold must be drilled out in places of reinforcement. They drill out the front in the place where the old connector will remain.

We remove the threshold amplifier, but do not forget to leave part of the old amplifier so that metal can be welded to it. When we have removed all parts of the threshold that were subject to corrosion, it is necessary to clean the rusty areas.

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Now you need to weld the purlin, on the subframe reinforcement, you need to overlap the connector; if it’s easier, then weld the joint into the joint with the old one.

Here you need to make the amplifier shorter and make a cutout in place of the stand. After this, we align the lower parts of the amplifier and connector. We take a welding machine in our hands and begin to weld the aligned body element from the center to the edges.

We level the threshold, adjust it to size and protect the places for welding seams. Using a drill, we will make holes for welding on the bottom of the panel. Then this part must be welded to the bottom, along with the connector. Finally, the metal is welded on the side of the upper part of the threshold, and patches are placed at the bottom.

In addition to everything, it is necessary to remove the welds, putty and paint, making sure it is tight. Replacing thresholds on classics is carried out in exactly the same way.

Repair cost

If you need to replace thresholds on a car, then it is worth considering that the price of work at a service station starts from 10,000 rubles. A comprehensive restoration of arches and wings will cost at least 25,000 rubles. The high cost is fully justified by the labor required by the craftsman and the cost of components. A common belief is that repairing body parts is a simple job and can take no more than an hour of time, rather than a marketing ploy.

You can save tenfold on repairs if you carry out the welding yourself in the garage. This is justified when the driver has minimal welding skills, knows the design of body elements, and understands what material needs to be used in what sequence. You won’t be able to save time; independent work, even with an assistant, rarely fits into 3 days; you need to be prepared to spend a week.

Why is it most profitable to come to our technical center for body repair of car thresholds?

1. Using high quality paint.
   The success of painting largely depends on the quality of paints and varnishes. We have a considerable number of shades of the most famous brands, which makes it possible to create up to 250 thousand different colors.
2. We only do body repairs.
   The Kaiser car service technicians only carry out body repairs. This allows us not to be distracted by other events, so we provide services as quickly as possible and at a high level.
3. Guarantee for work performed.
   For any procedure ordered in our auto repair shop, you are given a certain guarantee, so you can rest assured of the quality of the work performed, and if any violations arise due to our fault, we will repair them free of charge.
4. Great experience.
   Our car service (Michurinsky Prospekt St., Olympic Village) has been operating for more than 15 years. During this time period, we were able to attract a team of reliable experts who are able to carry out body repairs of any complexity.
5. Use of modern equipment.
   Body repair of thresholds requires the use of special equipment. Without this, violations may occur that will aggravate existing problems.
6. We work seven days a week.
   Our auto repair center (metro station Yugo-Zapadnaya) is open from 8-00 to 21-00, so you can come at any convenient time or make an appointment by phone.