(SEM V) THEORY EXAMINATION 2023-24 AUTOMOTIVE CHASSIS AND SUSPENSION

Subject Code: KAU052

Subject Name: Automotive Chassis and Suspension

Course: B.Tech (Semester V)

Maximum Marks: 100

Duration: 3 Hours

Exam Year: 2023–24

Sections: A, B, and C

SECTION A – Short Answer Questions (2 × 10 = 20 Marks)

Attempt all questions briefly.

What is a chassis? Name its different components.

Discuss the different materials used for making the frame.

Describe the different parts of clutch and state the function of each part.

Differentiate between differential and differential lock.

Describe the weight transfer phenomenon during braking in an automobile.

Discuss the different types of springs used in the suspension system.

Explain the significance of full floating axle.

Differentiate between oversteering and understeering.

Describe the requirements of wheels used in an automobile.

Explain the operation of the hill assist system.
 

SECTION B – Medium-Length Questions (10 × 3 = 30 Marks)

Attempt any three of the following:

Describe the layout of front-engine rear-wheel drive with a neat sketch.

Include advantages and disadvantages.

Discuss the working of a constant mesh gear box with the help of a sketch.

Explain the working of a MacPherson Strut with the help of a neat sketch.

Discuss the different types of steering gears used in steering systems.

Describe the construction and different parts of a tyre.
 

SECTION C – Long/Analytical Questions (10 × 5 = 50 Marks)

Q3. Vehicle Frame Layouts

a. Explain the different types of vehicle frames used in automobiles.
OR
b. Describe the layout of a front-engine, front-wheel drive vehicle with a sketch, mentioning its advantages and disadvantages.

Q4. Differential & Gear Design

a. Describe the function of a differential gear box with a neat sketch.
OR
b. A four-speed gear box is to be constructed with ratios 1.0, 1.46, 2.28, and 3.93:1 approximately.

Diametral pitch: 3.25 mm

Smallest pinion: ≥15 teeth

Centre distance (layshaft to main shaft): 78 mm
→ Evaluate suitable number of teeth on gears and determine exact gear ratios.

Q5. Suspension System

a. Describe the construction and working of a wishbone suspension system.
OR
b. A vehicle weighing 15,000 N, wheelbase 3 m, CG 1.5 m behind the front axle, and 0.8 m above ground.

Brakes applied on rear wheels only, speed = 15 m/s.
→ Calculate load distribution and stopping distance on level ground.

Q6. Steering Systems

a. Derive the condition for correct steering (Davis Steering Mechanism).
OR
b. A vehicle with Ackermann steering has:

Wheelbase = 280 cm

Front wheel track = 122 cm

Distance between kingpins = 108 cm

Maximum inner wheel deflection = 40°
→ Calculate turning radius of the outer front wheel.

Q7. Braking and Bearings

a. Explain the working of the Anti-Lock Braking System (ABS) with a neat sketch.
OR
b. Describe in detail the different types of bearings used for radial loads.
 

Key Topics to Study

Chassis & Frame

Components: Frame, suspension, steering, brakes, axles, wheels, and transmission.

Frame types: Ladder, tubular, monocoque, backbone.

Frame materials: Mild steel, aluminum alloys, composites.

Transmission & Differential

Constant mesh gearbox: Working, advantages, and gear arrangement.

Differential: Purpose, components, and function of differential lock.

Gear ratio numericals and design parameters.

Suspension Systems

Types of springs: Coil, leaf, torsion bar, air, and hydraulic.

MacPherson Strut and Wishbone suspension design and working.

Full-floating axle and weight transfer during braking.

Steering Mechanisms

Davis and Ackermann steering geometry and conditions for correct steering.

Oversteer vs Understeer analysis.

Tyres, Brakes & Bearings

Tyre parts: Tread, carcass, bead, sidewall, plies.

ABS function and components.

Bearings: Ball, roller, tapered, needle bearings.

Study Tips

Draw neat sketches — MacPherson strut, wishbone suspension, differential, and steering linkages.

Memorize formulas — braking distance, weight transfer, and turning radius.

Practice numericals — especially for gear ratios and steering geometry.

Revise real-world examples — such as front-engine layouts in common cars.

Understand systems integration — how suspension, steering, and chassis work together for vehicle stability.