8.1 Why is it important to use oil with a higher viscosity in a manual transmission? 8.2 Give the reason for using SAE20W50 oil in an internal combustion engine - NSC Mechanical Technology Fitting and Machining - Question 8 - 2018 - Paper 1

SAE20W50 oil is selected for internal combustion engines because it is designed to operate effectively over a wide range of temperatures. It provides proper lubrication during both start-up and normal operating conditions, thus ensuring that the engine runs smoothly and efficiently.

The pour point of a lubricant is defined as the lowest temperature at which the lubricant remains pourable. It indicates the temperature below which the lubricant may become too viscous to flow effectively.

1. Grease must be water-resistant or must not mix with water to provide effective lubrication in various environments.

2. It should have a low freezing point to ensure that it remains usable in cold conditions.

1. Regularly drain and replace the cutting fluid to avoid contamination.

2. Remove any metal chips that may accumulate in the machine's splash tray to maintain fluid effectiveness.

3. Check and ensure that there is sufficient flow of cutting fluid to the cutting tool to prevent overheating.

If the viscosity of the engine oil is too low, it will fail to maintain a sufficient lubrication film between the moving parts. This can result in increased friction, overheating, and ultimately accelerated wear and tear of the engine components.

Skimming the flywheel before installing a new clutch plate is essential to ensure a smooth and even surface. This practice helps to remove any wear grooves or irregularities, which can prevent the proper engagement of the clutch and lead to uneven wear or slippage.