What are five function of the gearbox oil in gear box?

Here are five simple functions of gearbox oil

Lubricates gears – Reduces friction and wear

Cools the gearbox – Carries away heat

Prevents rust – Protects metal parts from corrosion

Reduces noise – Makes gear operation smoother and quieter

Protects under heavy load – Handles high pressure between gears

In short:

Gearbox oil keeps gears smooth, cool, and protected.