What are the methods and skills for the correct selection of auto parts?

Check whether the trademark logo is complete. The quality of the outer packaging of the authentic product is good, the writing on the box is clear, and the overprint color is bright. The packaging box and bag should be marked with the product name, specification, model, quantity, registered trademark, factory name, address and telephone number, etc. Some manufacturers also mark their own marks on the accessories. Some important components, such as generators, distributors, fuel injection pumps, etc., are also equipped with instruction manuals, qualification certificates and inspector seals to guide users in correct use and maintenance. When purchasing, it should be carefully recognized to prevent buying fake and shoddy products.

See if the geometric size is deformed. Some parts are easily deformed due to improper manufacture, transportation and storage. During inspection, the shaft parts can be rolled around the glass plate to see if there is light leakage at the joint of the parts and the glass plate to judge whether they are bent; when purchasing the steel plate or friction plate of the clutch driven plate, the steel plate, friction Hold the sheet in front of your eyes to observe whether it is warped; when purchasing an oil seal, the end face of the oil seal with a skeleton should be in a perfect circle, which can fit with the flat glass without deflection; the outer edge of the oil seal without a skeleton should be straight and deformed by hand. , it should be able to return to its original state after letting go. When purchasing all kinds of pads, you should also pay attention to checking the geometric size and shape.

Check to see if the joint is flat. During the handling and storage of spare parts, due to vibration and bumping, burrs, indentations, damages or cracks are often generated in the joint parts, which affects the use of the parts. Pay attention to inspection when purchasing.

Check whether there is rust on the surface of auto parts. The surface of qualified spare parts has both a certain precision and a bright finish. The more important the spare parts are, the higher the precision is, and the stricter the packaging is to prevent rust and corrosion. When purchasing, you should pay attention to inspection. If the parts are found to have rust spots, mildew spots or cracks in the rubber parts, loss of elasticity, or obvious turning tool lines on the surface of the journal, they should be replaced.

Check whether the protective surface is intact. Most parts are factory coated with a protective coating. For example, the piston pin and bearing bush are protected with paraffin; the surface of the piston ring and cylinder liner is coated with anti-rust oil and wrapped with wrapping paper; the valve, piston, etc. are dipped in anti-rust oil and packaged in plastic bags. If the sealing sleeve is damaged, the wrapping paper is lost, the anti-rust oil or paraffin is lost when purchasing, it should be returned.

Check whether the glued parts are loose. For accessories composed of two or more parts, the parts are press-fitted, glued or welded, and no looseness is allowed between them, for example, the oil pump plunger and the adjusting arm are combined by press-fit; The clutch driven wheel and the steel plate are riveted and combined, the friction plate and the steel plate are riveted or glued; the paper filter element frame and the filter paper are glued together; the wire ends of the electrical equipment are welded. If it is found to be loose when purchasing, it should be replaced.

See if the rotating parts are flexible. When purchasing a rotating parts assembly such as an oil pump, turn the pump shaft by hand, and it should feel flexible and free from jamming; when purchasing a rolling bearing, support the inner ring of the bearing with one hand, and rotate the outer ring with the other hand, the outer ring should be able to rotate quickly and freely, and then Gradually stop. If the rotating parts do not turn smoothly, it means that the interior is corroded or deformed, so do not buy it.

See if there are any missing parts in the assembly. Regular assembly components must be complete and intact to ensure smooth assembly and normal operation. If the individual small parts on some assembly components are missing, the assembly components will not work or even be scrapped.