Before starting measurements on the slipway, it is necessary to clean the floor of the body and the power unit. Measurements are carried out with the help of special devices after the car is installed on the stand lift and the wheels are removed.
Subject to control:
- doorways;
- upper attachment points of the front suspension struts on the wheel casing;
- installation angles of the front and rear wheels;
- installation height of the steering gear housing.
The height and correct installation of the steering gear housing determine the directional stability of the vehicle during acceleration, braking and driving on uneven roads.
After carrying out inspection and repair work on the slipway, the following must be done:
- replace the ball joints of the front suspension arms and steering rods, and, if necessary, the steering mechanism;
- check the condition of the brake system, steering, wheel rims, tires and suspension elements;
- check and, if necessary, adjust the angles of the front and rear wheels.
The geometric dimensions of the car body frame and the points between which measurements should be taken are indicated in the Renault design documentation. For various inspection and repair slipways and stands, special sets of devices and computer-based documentation have been developed that simplify the performance of repair work.
Do not replace the welded structural members until the absence of deformation of the floor of the vehicle body has been confirmed.
It is usually difficult to detect minor body deformations resulting from moderate impacts to the front or rear of the vehicle. In case of doubt, suspicious places should be checked in an organoleptic way - by feeling the surface of the body with your fingers. Remove the noticed defects by editing and straightening.
If necessary, the complete removal of welded body parts is carried out at the welding points, partial - by cutting out the deformed section. The installation of a new element is carried out by welding, taking into account an allowance of approximately 20 mm.
Removal of contact welding points when removing damaged or deformed parts, the original shape of which cannot be restored by straightening directly on the vehicle, is carried out using a pneumatic chisel or drilling them with a carbide tool with a centering ledge.
It is necessary to cut metal from resistance welding points from the periphery to the center. In the event of serious damage to body parts (hood, fenders, etc.) replacement is recommended, since restoration is very often impractical, especially when parts can be purchased not only in auto parts stores, but also at disassembly, which can significantly reduce repair costs.
Features of welding work during body repair
In order to avoid failure of electrical equipment during welding, it is necessary to disconnect both terminals of the battery from the on-board network, it is advisable to remove the battery from the car.
Before disconnecting the battery, you should clarify the code combination of the car radio, since it can only be restored at the factory. The contents of the memory devices of other electronic devices in the car may also be lost, so the computer must be removed from the car.
Use only resistance spot welding methods. In cases where this is not possible, as an exception, it is allowed to use electric arc welding in a shielding gas environment.
Welding of galvanized parts must be carried out under forced ventilation conditions, since zinc oxide vapors released during welding are poisonous. In addition, it is necessary to take into account the technological requirements associated with the peculiarities of welding galvanized parts (increase in welding current by 10–30%, use of heat-resistant (up to 400°C) hard copper electrodes, electrode cleaning until a reliable contact spot with a diameter of 4 mm is formed, increased welding time).
Do not weld or solder air conditioner components filled with refrigerant.
Leveling tool
Currently, there are a large number of straightening hammers on sale, which are distinguished by a significant variety in weight, striker shape and material. The working part of straightening hammers is machined along the radius and must be polished. Traces of nicks, scratches, scratches or other damage on the head of straightening hammers are not allowed.
Hammers, the impact part of which is a flat striker, are not recommended for straightening the front surfaces of body panels, as they leave traces in the form of nicks on the metal.
Wooden hammers are used to straighten heavily deformed parts (mallets). In small deformed areas, straightening is carried out with a special hammer with a notch on the striker.
Light hammers, hammers- «trowels» used when removing small dents and nicks, when the front surface is brought under painting or when it is necessary to restore the surface without damaging the paintwork.
Hammers with plastic or rubber heads are used for final (thin) straightening painted surfaces.
Shaped plates, mandrels and anvils are designed to support thin sheet metal of body panels in the process of restoring deformed areas.
The working surfaces of these tools should always be well polished. To eliminate small dents or bulges without damaging the paint, the surfaces of some of the tools are brought to perfect cleanliness and chrome plated.