General information
The body of the car has a monocoque design. The front, side and rear parts of the body have zones of programmable energy-absorbing deformation. This means that they are able to absorb impact energy during the deformation process, thereby reducing the likelihood of injury to the driver and passengers of the car.
During the post-accident repair of the body, it is necessary to restore the geometric dimensions and strength of the body. During the restoration repair, both a decrease in the strength of the body and the strengthening of its individual parts are not allowed.
Body repair technology involves either extracting or replacing individual panels or their assemblies. The repair technology chosen in each specific case depends on the ratio of the cost of work and new body panels, as well as the availability of equipment and qualified specialists. The following factors also influence the decision: waiting time for repairs, the availability of a replacement vehicle, and the time it takes to complete the repair.
The task of the engineer is to select the optimal technology and ensure uniform utilization of production capacities. The instructions in this manual provide the body repairer with the recommended procedure for replacing body panels. The main goal of our recommendations is to bring the quality of repair work closer to the quality of a new car. The results of body restoration after an accident should not be noticeable even to an experienced expert, although the repair technology may differ from the factory technology. The equipment used for body repair is different from the equipment used during body fabrication at the factory.
When describing the work in this manual, the stage of carrying out the control of the car after the completion of the actual repair and restoration operations is omitted. It is very important that after the repair, a control of the work performed and a check of the suspension geometry and wheel alignment are carried out.
If necessary, a road test of the car should be carried out, especially if repairs have been made to systems that affect traffic safety.
If during the repair process the main units of the car were removed, then after reinstalling them, do not forget to check and, if necessary, restore the levels of oil, coolant and working fluids. It is also necessary to make sure that the external lighting devices are working, check the air pressure in the tires, the presence of fluid in the windshield washer reservoir, as well as the condition of other systems necessary for the normal operation of the car.
To carry out body repairs, it is often necessary to remove various mechanisms or components of electrical equipment and wiring. For correct removal and installation of components, refer to the instructions in the appropriate sections of this manual.
Body elements
Despite all the variety of body types, suspensions, engines and transmissions, it is necessary to ensure the correct location of the attachment points for the following components:
- The upper attachment points of the shock absorber struts of the front suspension.
- Attachment points for the front suspension or front subframe.
- The upper mounting points of the rear shock absorbers.
- Mounting points for lower rear suspension arms.
The following additional base points can be used to check body geometry:
- Internal openings in spars, floor cross members, main floor panel.
- Holes in the front spars.
- Holes in body sills.
- Holes in the rear rails.
- Openings in rear floor and luggage compartment floor.
The size of the openings of the windshield, rear door glass, bonnet and doors should be measured and compared with the values given, you can also take the size of the new element as a sample.
Elimination of deformations
If possible, the deformation of the structural elements of the body should be eliminated by mechanical action without heating the parts. Do not straighten the panels in one step, do the editing in several steps, after each stage check the geometry of the body and completely relieve the existing forces.
Body repair stand
Unless the repair involves decorative body panels, it should be carried out at a body repair bench to ensure that impact deformation does not extend to more distant elements of the body structure. Mounting the vehicle on a body repair stand ensures that the repair or replacement of individual panels does not cause additional distortion of the body geometry.
If this method fails to restore the original geometry of the part, the damaged load-bearing body parts must be replaced. Damaged sections of panels should be cut with a high-speed saw, NOT with an oxy-acetylene torch.
As a rule, all transverse dimensions of the body are symmetrical about the longitudinal axis of symmetry. Therefore, the initial diagnosis of body deformation should be carried out by diagonal measurements and an assessment of discrepancies in measurements.
Inspection
In every road traffic accident, various damages to the body occur. The organization of repair work is determined by the degree of damage to the body and the equipment that can be used for repair.
Most body damage can be detected visually, which allows an approximate assessment of their severity. Sometimes the impact deformation extends beyond the immediate damaged area. The degree of deformation must be accurately determined so that, as a result of the repair, the load-bearing elements of the body return to their original shape. Initial diagnosis can be performed using a plumb bob and caliper. Accurate measurement of body deformations can be performed using special instruments.
If during the repair it is necessary to replace the load-bearing elements of the body, it is recommended to use a body repair stand.
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