The car chassis is responsible for the connection and specification of car parts such as the engine, suspension and steering. There are different types of car chassis and they determine the type and performance of the car.
Without the chassis, the car cannot support its weight. Therefore, companies should be proficient in car parts to achieve an efficient car chassis design process. This article discusses the car structure and its common design trends so that companies can make more informed decisions.

What is an Automotive Car Chassis?

The chassis is the pillar of the car, the load-bearing part of the car frame and the minimum requirement for the car to move from one point to another. All the mechanical parts of the car, such as the steering system, suspension system, fuel tank, radiator, brakes, wheels, engine and transmission system are attached to the chassis.

Functions of an Automotive Chassis

The chassis of a vehicle has the following functions: Structural integrity of the vehicle The chassis supports the vehicle, provides a structural framework and determines how the vehicle collapses or deforms in a collision. Connection point for other components The chassis is the connection point for car components such as the steering and suspension systems, and its rigidity ensures correct alignment and installation. Aids in weight distribution A car’s chassis supports and distributes the vehicle’s load between the front and rear axles, making the car more stable or easier to handle.

Structure of Automotive Car Chassis

There are different designs of car chassis, but a traditional car chassis diagram will include the following structures, kits and components.

Frame Rails

Frame rails are longitudinal steel or aluminium beams that provide the load-bearing capacity of the chassis. There are many designs for different types of car chassis. For example, a stepped car chassis has two frame rails.

Cross member

Crossmembers are horizontal beams that connect the frame rails, increase chassis rigidity and act as load-bearing structures for other vehicle components.

Clutch

The clutch is a key component of a car’s chassis, connecting to the engine’s crankshaft and disengaging speed from the car’s transmission. Drivetrain The drivetrain or transmission is another key component of the car chassis, responsible for moving the car from one point to another. It transmits engine speed to the wheels and controls performance at different speeds.

Universal joint

The universal joint is a small connector behind the gearbox and front axle that connects torque from any direction and angle. It is used in the propeller shaft to transfer power from the engine to the wheels.

Rear axle

The rear axle is a live (rotating) chassis component divided into two halves (half-axles) connected by a differential to transmit power to the drive wheels.

Steering system

The steering system is divided into two types: hydraulic and electric, the former controlling the direction of the vehicle.

Braking system

The braking system is responsible for using friction to convert the rotational energy of the wheels into heat energy, thereby reducing the vehicle’s speed.

Types of Automotive Car Chassis

The chassis of a car is like a skeleton that carries the weight of the car. It has four major types that determine the performance and capabilities of the car. The four major types of car chassis are

  • Ladder Frame Chassis
  • Backbone Chassis
  • Monocoque Chassis
  • Tubular Chassis


The automotive chassis is responsible for the attachment and specifications of car components such as the engine, suspension, and steering mechanism. There are different types and they determine the type of vehicle and its performance.

Without a chassis, a vehicle cannot support the weight. As a result of this and its other influences, businesses should be well versed in the automotive part for an efficient automotive chassis design process. This article discussed the automotive structure and its common design trends so businesses can make more informed decisions.

What is an Automotive Car Chassis?

The car chassis is the car’s backbone acting as the load-bearing part of the car frame and is the minimum requirement for a vehicle to move from one point to another. 

All mechanical automotive components for example the steering system, suspension system, fuel tank, radiator, brakes, wheels, engine, and transmission system are fastened to the car chassis..

Functions of an Automotive Chassis

The chassis of a car is responsible for the following: 

Vehicle structural integrity

The chassis supports the vehicle, providing the structural framework that determines the collapse or deformation of the vehicle in a collision. 

Point of attachment for other components

It is the attachment point for auto components like the steering system and suspension system and its rigidity ensures proper alignment and mounting. 

It helps in weight distribution

The car chassis bears and distributes the vehicle’s load between the front and rear axles making the car stable or easier to handle. 

Structure of Automotive Car Chassis

Automotive chassis come in different designs but a  conventional car chassis diagram will contain the following structure, kit, and components. 

Frame Rails

A frame rail is a steel or aluminum longitudinal beam responsible for the chassis load-bearing ability. There are several designs responsible for the different types of car chassis. For example, ladder car chassis have two frame rails.

Crossmember

A crossmember is a horizontal beam that connects the frame rails increasing the chassis rigidity and its functions as a load-bearing structure for other auto components.

Clutch

The clutch is a main car chassis part connected to the engine crankshaft and disconnects the speed from the car gearbox. 

Transmission system/gearbox

The gearbox or transmission system is another critical chassis responsible for a vehicle’s ability to move from one point to another. It transmits the engine speed to the car wheel and controls its performance at different speeds. 

Universal Joint

The universal joint is a little connector behind the transmission and front axle, connecting the torsional moments from any direction and angle. It is used in the drive shaft to transfer energy from the engine to the wheels. 

Rear Axle 

The rear axle is a live chassis component (it rotates) that comes in two halves (half shafts) connected by the differential that delivers power to the driving wheels. 

Steering system

The steering system has two types: the hydraulic type and the electric type which controls the vehicle’s direction. 

Braking system

The braking system is responsible for reducing the vehicle’s speed by using friction to convert the wheel’s rotational energy into heat energy.

Types of Automotive Car Chassis

The chassis of a car is likened to its skeleton bearing the car’s weight. It has four main types that can determine the car’s performance and abilities. The four main types of car chassis are:

Ladder Frame Chassis

The ladder frame chassis has a unique ladder design (hence the name) and is the oldest chassis in the automobile industry. It is characterized by two long heavy beams supported by two smaller ones. 

Based on the design, it is easy to construct, but it is very heavy and only suitable for large vehicles, such as trucks, trailers, etc., that carry heavy materials. 

Benefits

  • Easy construction and assembling process
  • High structural integrity 

Drawbacks

  • Weak torsional rigidity
  • Poor cornering ability 
  • Highly heavy, making it unsuitable for performance cars and hatchbacks.

Backbone Chassis 

The backbone chassis is also named according to its shape, as it resembles the backbone of a human. It is a hollow cylindrical tube that connects the front and rear suspension. Also known as the single chassis, it is common in off-road cars due to its torsional toughness. 

Benefits

  • Preferable for off-road cars.
  • High torsional toughness 

Drawbacks

  • If the driveshaft fails, the whole chassis will be dismantled 
  • High cost of manufacturing 

Monocoque Chassis

In the monocoque automobile chassis, the frame and the chassis come together to form a single shell. Also known as the unibody design, it is the most common chassis in modern normal cars such as SUVs, sedans, and cabs. 

Benefits

  • High torsional rigidity
  • Safer due to its cage-like design
  • Easy maintenance and repair

Drawbacks

  • It is heavy due to the fused frame and chassis 

Tubular Chassis

A tubular chassis is a 3D derivative of a ladder chassis made with tubular pipes (hence the name) with the vehicle component designed around the chassis. They are found in race cars because they are safer. 

Benefits

  • Higher rigidity than other frames with similar weight
  • High strength-to-weight ratio 

Drawbacks

  • It has a complicated design and construction 
  • Unsuitable for mass production 
  • Used for drag and normal racing cars
  • Difficulty in accessing the cabin due to elevated doors 

Common Automotive Car Chassis Process

The car chassis processes used in the automotive industry depend on factors such as the car chassis component, type, cosmetic material, design, and production volume. Manufacturing processes include

  • Sheet Metal Fabrication
  • CNC machining
  • Die Casting

Common Material for Car Chassis

  • Steel
  • Aluminum
  • Composite materials
  • Magnesium alloys

Common Surface Finishes for Car Chassis  

Lapping
Buffing
Galvanization
Anodizing
Painting

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