CLS Lubricant Selection & Management 3

Question 1

A worm gear drive requires a lubricant to handle sliding contact between steel and bronze components. Which additive type should be avoided?

Accepted Answer

Sulfur-based EP additives

Answer

Sulfur-based EP additives corrode bronze and other yellow metals, making them unsuitable for worm gear drives with bronze components.

Question 2

The Viscosity Index (VI) of a lubricant measures its:

Accepted Answer

Rate of viscosity change with temperature

Answer

Viscosity Index quantifies how much a lubricant's viscosity changes with temperature; a higher VI means less viscosity change.

Question 3

Which synthetic base oil type offers the best performance for very wide operating temperature ranges, from -60°F to +400°F?

Accepted Answer

Silicone fluid

Answer

Silicone fluids maintain usable viscosity across extremely wide temperature ranges, from very low to very high temperatures, surpassing PAOs.

Question 4

A technician notices a gear oil has turned milky white in color. This most likely indicates:

Accepted Answer

Water contamination

Answer

A milky or cloudy white appearance in gear oil is a classic sign of water emulsification or contamination.

Question 5

When lubricating an open gear drive exposed to washout and contamination, which lubricant form is most appropriate?

Accepted Answer

Asphaltic (bituminous) open gear compound

Answer

Asphaltic open gear compounds provide extreme adhesiveness and high film thickness to cling to teeth and resist wash-off under harsh exposure.

(CLS) Certified Lubrication Specialist Practice Test