The Difference between Gear Oil and Transmission Fluid
The terms “gear oil” and “transmission fluid” are often used interchangeably, but there are important differences that need to be understood in order to choose the right lubricant for a vehicle.
What is Gear Oil?
Gear oil is a thick oil designed to lubricate the gears, shafts and other components of mechanical transmissions or transfer cases in cars, trucks and other vehicles with manual transmissions. Gear oil is thicker and heavier than engine oil and is usually a mineral oil with additives to provide extra protection against wear.
What Is Transmission Fluid?
Transmission fluid is a type of lubricant used in transmissions and other parts of a vehicle with an automatic transmission. Unlike gear oil, transmission fluid is usually much thinner and contains additives to provide smoother shifting and to protect the transmission from wear and damage.
The Difference Between Gear Oil and Transmission Fluid
The main difference between gear oil and transmission fluid is their composition:
- Gear Oil is thicker, heavier and designed to protect the gears and other components in a manual transmission.
- Transmission Fluid is thinner and designed to provide smoother shifting in an automatic transmission.
Gear oil and transmission fluids may look similar, but it’s important to use the right one to ensure the longevity of a vehicle. It is therefore critical to consult a vehicle’s owner manual before adding any lubricant to the transmission.