Answer ANY THREE questions from this section Each question carries 20 marks 11. (a) With the aid of a diagram explain the power flow in a four-speed manu transmission gearbox. (10 marks) (b) Discuss five factors that affect the efficiency of a manual transmission s marks) 12. (a) Describe the major components of an automatic transmission system an functions. (10 marks) (b) Explain the role of hydraulic fluid in an automatic transmission system marks) 13. (a) With the help of a diagram, describe the working mechanism of a diffe system. (10 marks) (b) Explain the difference between limited-slip and open differentials. (10 14. (a) Discuss five causes of transmission system failure and their remedies. (b) Explain the step -by-step procedure for diagnosing a faulty transmissio (10 marks)

1. Power Flow in a Four-Speed Manual Transmission Gearbox<br /> A four-speed manual transmission uses gears to transmit power from the engine to the wheels. The diagram typically shows input shaft, countershaft, and output shaft with gear pairs for each speed. Power flows from the engine to the input shaft, through selected gear pairs on the countershaft, and finally to the output shaft.<br /><br />2. Factors Affecting Efficiency of Manual Transmission<br /> Five factors include: <br />1. **Gear Design**: Precision affects friction and efficiency.<br />2. **Lubrication**: Proper lubrication reduces wear and friction.<br />3. **Material Quality**: High-quality materials reduce energy loss.<br />4. **Alignment**: Misalignment increases resistance.<br />5. **Driver Skill**: Smooth shifting minimizes energy loss.<br /><br />3. Major Components of Automatic Transmission System<br /> Key components include:<br />1. **Torque Converter**: Transfers engine power to transmission.<br />2. **Planetary Gear Set**: Provides different gear ratios.<br />3. **Hydraulic System**: Controls gear shifts using fluid pressure.<br />4. **Electronic Control Unit (ECU)**: Manages shift timing and patterns.<br />5. **Transmission Fluid**: Lubricates and cools components.<br /><br />4. Role of Hydraulic Fluid in Automatic Transmission<br /> Hydraulic fluid transmits power, lubricates moving parts, cools the system, and facilitates smooth gear shifts by controlling hydraulic pressure.<br /><br />5. Working Mechanism of Differential System<br /> Differentials allow wheels to rotate at different speeds, especially during turns. The diagram shows gears that distribute torque between wheels, enabling smooth cornering.<br /><br />6. Difference Between Limited-Slip and Open Differentials<br /> **Open Differential**: Allows wheels to spin independently; can lose traction easily.<br />**Limited-Slip Differential**: Reduces wheel spin by distributing torque more evenly when traction is lost.<br /><br />7. Causes of Transmission System Failure and Remedies<br /> Common causes include:<br />1. **Overheating**: Remedy by ensuring proper cooling.<br />2. **Fluid Leaks**: Fix leaks and maintain fluid levels.<br />3. **Worn Gears**: Regular inspection and replacement.<br />4. **Clutch Problems**: Adjust or replace clutch components.<br />5. **Electrical Issues**: Diagnose and repair faulty wiring or sensors.<br /><br />8. Procedure for Diagnosing Faulty Transmission<br /> Steps include:<br />1. **Check Fluid Levels**: Ensure proper fluid levels.<br />2. **Inspect for Leaks**: Identify and fix any leaks.<br />3. **Test Drive**: Observe performance issues.<br />4. **Scan for Error Codes**: Use diagnostic tools to find electronic faults.<br />5. **Physical Inspection**: Check mechanical components for wear or damage.