Where is the frame of a car located?
3 Answers
The frame of a car is part of the chassis structure. There are two channel steel beams running from the front to the rear of the car, which constitute the frame. Below are detailed introductions about the car frame: Composition of the car frame: The frame serves as the base of the car, supported by the suspension system, front axle, and rear axle on the wheels. The frame generally consists of longitudinal beams and cross beams. Types of frames: There are mainly two types: side rail frame and central backbone frame. The side rail frame is composed of two longitudinal beams on the sides and several cross beams, connected by riveting or welding to form a sturdy rigid structure. Function of the frame: The frame must have sufficient strength and rigidity to bear the car's load and impacts transmitted from the wheels. Its function is to support and connect various assemblies of the car, ensuring they maintain relatively correct positions, and to withstand various internal and external loads.
The vehicle frame is actually located beneath the chassis, running from the front to the rear of the car like two parallel steel skeletons. My SUV features a typical body-on-frame design, and during every maintenance session when it's lifted, I can clearly see those two 10-centimeter-high longitudinal beams spanning the chassis. They're made of high-strength steel in a channel shape, with the front section connected to the engine mount and the rear section supporting the rear axle. Last time during off-roading when the vehicle got stuck, the frame directly hit a rock with a loud clang, but the car didn't deform at all. This design allows the body to sit on the steel beams like a house, making it fearless even when twisting on rough roads. It might not be as obvious in regular sedans, but if you remove the underbody panels, you can find similar reinforced longitudinal beam structures.
The easiest way to find the vehicle frame is to crawl under the car and look at both sides of the chassis. Starting from behind the front bumper, you'll see two sturdy metal beams running the entire length of the body, most visible between the front and rear wheels. The frame on my pickup truck is as wide as a palm, with various brackets welded to it supporting the fuel tank and drive shaft. Even unibody sedans have similar structures, though they're welded together with the floor pan. After a rear-end collision, the mechanic at the repair shop pointed to the deformed left frame rail and said this is the vehicle's true backbone - more important than the A, B, or C pillars. It's normal not to see it in daily use since it's hidden right below the door sill; you need to lift the vehicle to observe it completely.
