This was a question on lubrication. Most of the candidates could not define viscosity and viscosity index. Viscosity is a measure of an oil's ability to flow. Viscosity index is the number given to oil to indicate its resistance to flow as the temperature changes or the measure of the change in an oil's viscosity when heated or cooled.
2(b) I was on type of lubrication but some candidates based their answers on types of lubricant and got the answer wrong. Other candidates claimed that a 2-stroke S. l engine uses splash lubrication when it uses petrol. .
The grade of oil suitable for the rear axle is not hydraulic oil or SAE40 as stated by most of the candidates. Rear axle makes use of SAE 70 -140EP. SAE90, 12001'140. Most of the candidates were able to state that grease is used for the hub bearing as lubricant.
Part C of the question required the candidates to sketch a gear type oil pump and label any three of its parts" Most of the candidates' sketched wrong figures like figure g and h below.
Candidates were awarded their marks when the parts (only three) were correctly labelled. Some candidates did not label but just wrote down three party of the pump and did not get any mark. The correct sketch required is shown below and duly labelled.
