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 used in internal combustion engines because it can maintain its viscosity over a wide range of operating temperatures. This ensures that the engine remains well-lubricated during both start-up and when operating at normal temperatures, thereby enhancing performance and preventing engine wear.

The pour point of a lubricant is defined as the lowest temperature at which the lubricant remains pourable. Below this temperature, the lubricant may solidify or become too viscous to flow, which can impair its performance in machinery.

1. Grease must be water-resistant or should not mix with water to be effective in preventing corrosion.
2. Grease should have a high melting point, allowing it to perform well under high temperature conditions without breaking down.

1. Regularly drain and replace the cutting fluid to avoid contamination.
2. Remove metal shavings and debris from the machine's splash tray to maintain fluid cleanliness.
3. Ensure that the pump supplying the cutting fluid is checked and serviced regularly to ensure adequate flow.

If the viscosity of the oil in an internal combustion engine is too low, the oil will not provide adequate lubrication between moving parts. This can lead to increased friction, overheating, and ultimately, accelerated wear and potential failure of critical engine components.

Skimming the flywheel ensures a flat and smooth surface that promotes optimal contact between the flywheel and the new clutch plate. This process helps to eliminate any warps or unevenness in the surface, which is critical for achieving proper engagement and preventing slipping of the clutch.