MDE 10 End of Unit Quiz

Correct Answers: A) Replace worn or damaged gears
C) Adjust or realign misaligned gears

Explanation:

• Replace worn or damaged gears: Worn or damaged gears can increase friction and cause operational issues. Replacing them with new gears addresses the root cause of the excessive friction.
• Adjust or realign misaligned gears: Misaligned gears can cause excessive friction and wear. Correcting the alignment ensures smooth engagement and operation of the gears, reducing friction.

Note: Increasing the gearbox oil temperature and decreasing the oil level are not effective solutions for dealing with friction issues due to worn or misaligned gears. Using a different type of lubricant might help in some cases but does not address the underlying mechanical issues with the gears themselves.

Correct Answer: B) Total Base Number (TBN)

Explanation: The Total Base Number (TBN) measures the oil’s ability to neutralize acidic byproducts from combustion. A higher TBN indicates better capacity to protect engine parts from acid corrosion.

Correct Answer: A) To ensure adequate cooling and prevent overheating of gearbox components

Explanation: Large quantities of lubricating oil in a gearbox are used primarily to ensure proper cooling and to prevent overheating of the gearbox components. The oil helps absorb and dissipate heat generated by the friction and mechanical work within the gearbox, maintaining operational efficiency and preventing damage.

Explanation:

• A) Increased friction and wear: Insufficient lubrication causes increased friction between moving parts, leading to overheating and accelerated wear, which can result in engine damage and failure.
• B) Improved engine efficiency: This is incorrect. Insufficient lubrication does not improve engine efficiency. Instead, it increases friction and reduces efficiency.
• C) Decreased oil consumption: This is incorrect. Insufficient lubrication typically leads to increased oil consumption due to the need for additional oil to manage the increased friction and wear.
• D) Enhanced engine performance: This is incorrect. Insufficient lubrication generally degrades engine performance by causing excessive friction, overheating, and potential damage.

Explanation:

• A) Grease can become less effective at high temperatures compared to oil: Correct. Grease can degrade or become less effective at higher temperatures compared to oils, which often have higher temperature tolerances.
• B) Grease requires frequent re-lubrication compared to oil: Incorrect. One advantage of grease is that it generally requires less frequent re-lubrication compared to oil due to its thicker consistency and staying power.
• C) Grease can attract dust and debris, leading to potential contamination: Correct. Grease can attract dust and debris due to its sticky nature, which can lead to contamination of the bearing and reduced lubrication effectiveness.
• D) Grease provides less protection against corrosion compared to oil: Incorrect. Grease often provides good protection against corrosion due to its ability to stay in place and its additives.

Explanation:

• A) Reduces friction between engine components: Correct. One of the primary functions of lubricating oil is to reduce friction between moving parts, which minimizes wear and improves engine efficiency.
• B) Enhances fuel combustion efficiency: Incorrect. While lubricating oil affects overall engine performance, it does not directly enhance fuel combustion efficiency.
• C) Cools engine components by carrying away heat: Correct. Lubricating oil helps to dissipate heat generated by engine components, contributing to engine cooling.
• D) Cleans engine parts by suspending contaminants: Correct. Lubricating oil helps to remove and suspend contaminants such as dirt and metal particles, keeping the engine clean.
• E) Seals gaps between moving parts: Incorrect. Lubricating oil does not seal gaps; it primarily reduces friction and helps in cooling and cleaning.
• F) Protects engine parts from corrosion and rust: Correct. Lubricating oil contains additives that protect engine parts from corrosion and rust.

Correct Answer: C) Maintaining proper oil temperature

Explanation: Maintaining the proper oil temperature is crucial for ensuring that the lubricating oil remains in good condition. Proper temperature helps in reducing oxidation and ensures the oil's viscosity remains within the optimal range for effective lubrication.

B) Ensures more uniform oil distribution and control of oil flow

Explanation: Forced circulation lubrication provides better control and uniform distribution of oil compared to splash lubrication. The use of a pump ensures that oil is delivered precisely where it is needed, including the cylinder liners, which improves lubrication efficiency and engine performance.

Correct Answer: A) Viscosity

Explanation: Viscosity is essential for preventing metal-to-metal contact because it determines the oil’s ability to maintain a lubricating film between moving parts. A proper viscosity ensures that the oil can form a thick enough film to prevent wear.

Explanation:

• A) Increased oil consumption: Excessive lubrication often results in higher oil consumption because surplus oil can leak or be burned off, leading to a need for more frequent topping up.
• B) Reduced friction: This is misleading. While lubrication does reduce friction, excessive lubrication does not necessarily lead to reduced friction; it can cause other issues such as oil foaming.
• C) Increased risk of oil foaming: Excessive lubrication can lead to oil foaming, which decreases the effectiveness of lubrication and can cause engine damage due to poor oil film formation.
• D) Enhanced cooling: This is incorrect. Excessive oil does not necessarily enhance cooling and can actually lead to problems such as oil foaming, which impairs the cooling function.

Correct Answer: C) It ensures adequate lubrication of engine components.

Explanation: Maintaining proper oil levels is critical for ensuring that all engine components receive adequate lubrication, reducing wear and tear and keeping the oil in a satisfactory condition.

Correct Answer: B) Condensation of water vapor

Explanation: Water contamination can occur due to condensation of water vapor inside the engine, especially in cooler environments. This can mix with the lubricating oil and degrade its performance.