What type of oil is used in a manual transmission car's gearbox?
3 Answers
Manual transmission cars use 75W gear oil. Transmission oils are divided into two types: manual transmission oil and automatic transmission oil. Manual transmission oil is gear oil, while automatic transmission oil is also known as transmission fluid or driveline oil. The steps for changing transmission oil are: 1. Drain the old oil; 2. Remove the oil pan; 3. Install the drain plug and pour in new oil. The reasons for changing transmission oil are: 1. Over time, the viscosity of transmission oil becomes diluted, reducing its lubricating and sealing properties, increasing resistance, leading to greater wear and affecting the accuracy of the hydraulic system; 2. The oil deteriorates, reducing its anti-oxidation and cooling properties, causing excessively high oil temperatures and shortening the lifespan of transmission components.
I've always driven manual transmission cars, and this is a common issue. Manual transmission fluid typically uses GL-4 or GL-5 gear oil, depending mainly on the vehicle's synchronizer design. Most modern cars recommend GL-4, with 75W-90 being the primary viscosity. For older models, GL-5 might be used, but never mix them up, as it can cause gear shifting to become rough or even damage the transmission. I suggest checking the owner's manual first, as it specifies the type based on brand and year—for example, Japanese cars often use GL-4 full synthetic oil. For regular maintenance, I stick to changing the fluid every 50,000 miles or two years. Choosing reliable brands like Mobil or Castrol can improve shift smoothness and fuel efficiency. Neglecting oil quality may lead to increased noise or accelerated wear, so periodic checks are essential.
As a DIY enthusiast, I've changed my transmission oil multiple times. The preferred specification is GL-4 75W-90, with synthetic oil offering better durability. The process is straightforward: lift the car, locate the drain plug, drain the old oil, and refill with new oil. Price-wise, a 1L bottle costs around 20-30 RMB—don't skimp on quality. Some vehicles, like American models, perform better with low-viscosity oil for fuel efficiency, but always check the manual. Using GL-5 in a GL-4-required transmission can corrode synchronizers; a friend faced this issue, costing thousands in repairs. I recommend keeping a repair guide app handy to verify specs beforehand. In daily driving, oil quality affects acceleration response, and regular maintenance saves big in the long run.
