Loosen the Screws First or Jack Up the Car First?
2 Answers
When changing a car tire, use a wrench to loosen the screws before jacking up the car body. Here are the detailed introductions about the car jack: 1. Definition: A car jack is a small lifting device that uses a rigid lifting component as the working device to lift heavy objects within a small stroke through the top support seat or bottom support claw. Car jacks are mainly used in factories, mines, transportation, and other sectors for vehicle repairs and other lifting and supporting tasks. They are lightweight, sturdy, flexible, and reliable, and can be carried and operated by one person. 2. Classification: Car jacks can be divided into three types according to their structural characteristics: rack jacks, screw jacks, and hydraulic jacks. According to other methods, they can be classified into separate jacks, horizontal jacks, claw jacks, synchronous jacks, hydraulic jacks, electric jacks, etc. Among them, commonly used jacks include screw jacks, hydraulic jacks, electric jacks, etc.
I always strongly recommend jacking up the car before loosening the lug nuts, because loosening the nuts while the car is still on the ground can make them come loose. During the jacking process, the car may tilt or shift, which is very dangerous! I remember when I was learning car repairs from my dad as a kid, he repeatedly emphasized: always park on level ground first, engage the handbrake, place wheel chocks, and then use the jack to steadily lift the car until the tire is about one centimeter off the ground. Only then can you safely loosen or remove the lug nuts. I also recommend gently pushing the car after lifting to check its stability; after finishing, make sure all nuts are properly tightened before slowly lowering the jack. Additionally, developing the habit of wearing gloves and using high-quality tools can prevent accidental cuts. In short, safety should always come first—don’t skip this crucial step just to save time.
