Gear oil (transmission fluid) lubricates all the gears, bearings, and synchronisers inside your gearbox — whether manual or automatic. It prevents metal-to-metal contact under the extreme pressure of gear changes, keeps the transmission cool, and enables smooth, precise shifting. Old or low transmission fluid causes rough or delayed gear shifts, grinding noises, overheating, and can ultimately lead to complete gearbox failure — a repair that often costs more than the vehicle is worth.
Transmission repairs are among the most expensive in automotive servicing. Gear oil is one of the most overlooked fluids — most drivers never think about it until something goes wrong. A simple periodic check can prevent a repair bill that's multiples of the car's service cost.