Chassis, its fabrication and Automotive body. Automotive Chassis and Transmission

These are the first two chapters of the subject ACT that can be studied together. They contains 10% weightage together i.e. 5% + 5%. 

So lets start with the very first topic. 



Classification of automobiles:

Automobiles may be classified into many sorts supported many criteria. a quick classification of vehicles is listed below:


1. based on purpose:


* Passenger vehicles – These vehicles carry passengers – e.g: Buses, traveller trains, cars

* Goods vehicles – These vehicles are used for transportation of products from one place to a different. e.g: goods lorry, goods carrier


oyetechy, auto 5th sem
Pic 1: Goods Lorry


2. based on capacity:


* Heavy motorized vehicle (HMV) – large and bulky motor vehicles – e.g: massive trucks, buses

* Light motorized vehicle (LMV) – small motorized vehicles – e.g: Cars, Jeeps
* Medium Vehicle – comparatively medium sized vehicles – e.g: small trucks, mini buses


3. based on fuel source:


* Petrol engine vehicles – vehicles power-driven by petrol engine – e.g: scooters, cars, mopeds, motorcycles

* Diesel engine vehicles – Automotives power-driven by diesel engine – e.g: Trucks, Buses
* Gas vehicles – Vehicles that use gas turbine as power supply – e.g: turbine powered cars
* Solar vehicles – Vehicles considerably power-driven by solar energy – e.g: solar powered cars
* Hydrogen vehicles – Vehicles that have hydrogen as a power supply – e.g: Honda FCX Clarity
* Electric vehicles – vehicles that use electricity as a power supply – e.g: electrical cars, electrical buses
* Steam Engine Vehicles – Automotive power-driven by steam engine – e.g: boat, locomotive, steam wagon
* Hybrid Vehicles – Vehicles that use two or more than two power sources – e.g: Hybrid buses, hybrid cars like Toyota Prius, Honda Insight
* Hybrid electrical Vehicle (HEV) – Automobile that uses both internal combustion Engine and electric power supply to propel itself – e.g: jaguar C-X75

4. based on type of transmission:


* Automatic transmission vehicles – vehicles that are capable of adjusting gear ratios automatically as they move – e.g: automatic transmission Cars

* Conventional transmission vehicles – Vehicles whose gear ratios have to be changed manually
* Semi-automatic transmission vehicles – Vehicles that do manual gear changing with clutch pedal


5. based on number of wheels:


* Two wheeler – vehicles having 2 wheels – e.g: Scooters, motorcycles

* Three wheeler – Automotive having 3 wheels – e.g: Tricycles, automotive vehicle rikshaws, Tempos
* Four wheeler – Vehicles having four wheels – e.g: Car, Jeep
* Six wheeler – Automobile having six wheels used for serious transportation – e.g: giant trucks, giant buses


Pic 2: Four Wheeler,  Mahindra XUV


6. based on the side of drive:


* Left hand drive automobile – Vehicle in which steering wheel is fitted on the left hand side – e.g: vehicles found in USA, Russia

* Right hand drive automobile - Vehicle in which steering wheel is fitted on the right hand side – e.g: vehicles found in India, Australia.


Layout of a conventional type Chassis:



oyetechy, technical
Pic 3: Conventional Chassis
Types of drives of vehicle:

Some of the necessary drives of cars may be classified as follows:


1. Front engine - Rear wheel drive

2. Rear engine - Rear wheel drive
3. Front engine - Front wheel drive
4. Four wheel drive

1. Front Engine - Rear Wheel Drive


In this layout a front mounted engine-clutch-gear box unit drives a beam type rear axle suspended on leaf sprints through a mechanical device shaft with 2 universal joints. With the assistance of coil sprints, the front wheels are independently sprung.

A number of the benefits provided by this method are :
(a) Balanced weight distribution between the front and therefore the rear wheels.
(b) easy front wheel steering.
(c) Behind the rear seats, massive luggage area is accessible.
(d) Accessibility to varied parts like engine, gearbox and rear axle is better in comparison to alternative layouts. The control linkages-accelerator, choke, clutch and gearbox square measure short and easy.
(e) Full benefits of the natural air stream created by vehicle’s movement is taken by the forward radiator leading to reduced power losses from an outsized fan.
(f) small length of the propeller shaft permits the angularity of the universal joints to be little and simply provided by simple types.
By mounting the rear wheel drive assembly on the body unit and using universally jointed shafts to severally steer rear wheels  It provides variety of advantages like improved handling, comfort and rear wheel grip likewise as reduced unspring weight.

2. Rear engine-Rear wheel drive


This arrangement eliminates the requirement for a propeller shaft when the engine is mounted adjacent to the driven wheels. The engine-clutch-gear box-final drive form a single unit during this layout.. as compared to front wheel drive it's an easier drive shaft layout. Further, the load of rear engine on the driving wheels provides wonderful tranction and grip particularly on steep hills likewise as when accelerating. Inspite of the low proportion of the vehicle weight transferring to the front wheels, very effective rear wheel braking is possible. thanks to the absence of the propeller shaft the obstructed floor space is reduced. The front of the vehicle will, therefore, be designed for good visibility and swish air flow. the exhaust gases, fumes, engine heat and noises are frenzied from the passengers. It ends up in compact layout and short automotive. The layout conjointly possesses bound disadvantages like restricted baggage area due to narrow front compartment that houses the fuel tank also. Natural air cooling isn't possible, it needs a strong fan. the floor is further closed due to long linkage needed for the engine, clutch and therefore the gear box controls. The rearward concentration of weight causes the vehicle to be additional affected by side winds at high speeds. this makes the vehicle unstable leading to over steering and turning terribly sharply into a curve. This requires the steering correction in the opposite direction.


3. Front engine-front wheel drive


This layout provides optimum body-luggage area and a flat floor line leading to a crosswise longitudinal engine position. This drive pulling the car along provides good grip and sensible road holding on curves due to major weight at the front. the probabilities of skidding particularly on slippery surfaces are pretty much reduced. sensible road adhesion is provided by the large proportion of the vehicle weight acting on the driven wheels. when the vehicle is to be ‘steered in’ to the curve, it provides ‘understeer’ characteristics always most well-liked by drivers.

The combination of steered and driven wheels with short drive shafts provides the most disadvantage. this needs special universal joints and a more sophisticated assembly. to stop the rear wheels from skidding underneath serious braking, the ‘reduced’ weight at the rear sometimes necessitates special arrangement.

4. Front wheel steering Rear wheel drive


1. Access to the engine is extremely simple.

2. slowing down of the water circulation causing cooling troubles may be avoided and long hose connections may be saved because of situating of the radiator within the main air stream.
3. This arrangement helps minimize the linkage between the clutch, gear box and engine.
4. The angularity of the propeller shaft is kept to minimum and there's no need of joints due to the shaft length.

Concept of multiaxle:

Multi axle is a system in which the weight of the vehicle is carried by more than 2 axles. This is implemented mostly due to weight restrictions and sometimes, to provide better suspension and comfort. Most common examples are volvo multi axle buses that you must have seen around.

Classification of Automotive Bodies:

1. Convertibles
2. Coupe
3. Crossover 
4. Hatchback
5. Luxury
6. MUV or ulti Utility Vehicle
7. Notchback
8. Sedan 
9. Sports car
10. SUV or Sports  Utility Vehicles
11. Wagon 
12. Supercars
13. Van/Minivan

Importance of Automotive Body Design:

Vehicle body is a superstructure. Body is either integral with the underneath frame or fastened to the frame. The body & chassis create complete vehicle. A body encompass a doors, windows, engine covers, roof, luggage, cover etc. different variety of body's is attached to chassis according to application.
The necessary design concerns are as follows:
i)Customer appeal of fashion
ii)Reduction in weight to enhance capability & fuel economy.
iii)Aerodynamic characteristics that determine the fuel consumpton, speed. &_stability in cross wind. The positive pressure at front ought to be reduced & deflated smoothly for the interference of eddies creations.

Materials for body work:
Steel is employed in majority of cases being the most affordable together with the benefit with that it can be stamped out to form numerous shapes. Alloying elements are added improve its ability to be formed into deeper depressions while not wrinkling or tearing within the producing presses. aluminium has additionally been utilized by some makers owing to its higher formability, lightness & anti-rusting qualities, although its main disadvantage is lesser stiffness & rigidity.
Thermoplastics are very often used for elements like boot cover, grills, etc. fiberglass are being employed for the body shells.

Toughened or tempered glass has been used for the car windshield & different window panes laminated glass is employed for windshield.


Note: For any queries or questions you can directly mail me. Or just DM me on instagram @chakitg. 


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Regards: 

Er. Chakit Gupta

Chassis, its fabrication and Automotive body. Automotive Chassis and Transmission Chassis, its fabrication and Automotive body. Automotive Chassis and Transmission Reviewed by Oyetechy.com on October 31, 2019 Rating: 5

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