What does it mean when the transmission dipstick has 4 markings?
2 Answers
An automatic transmission dipstick has two inspection zones. The upper two markings indicate the upper and lower limits for checking when the engine is hot, while the lower two markings indicate the upper and lower limits for checking when the engine is cold. Here is some information about automotive transmission fluid: 1. Transmission fluid: Transmission fluid is a lubricant that keeps the gear system clean, ensuring the normal operation of the transmission and extending the lifespan of the transmission components. 2. Characteristics: Most transmission fluids can be used in automatic transmissions available on the market. In fact, each automatic transmission design has different technical requirements. Even the same model of transmission configured in different vehicles may have differences in torque, weight, speed, and structure. Therefore, the original manufacturer specifies its own dedicated transmission fluid. Different transmission fluids are one of the factors that affect the quality of gear shifting.
When I delved deeper into automotive design, I discovered the cleverness of the four marks on the transmission dipstick. They are actually designed to accommodate oil level changes at different engine temperatures. During a cold start, the oil volume is smaller and more viscous, so there are two marks specifically indicating the minimum and maximum safe oil levels in cold conditions. After the engine warms up, the oil expands and becomes thinner, leading to two additional marks for measuring in warm conditions. If you casually check the dipstick without distinguishing between cold and warm states, it's easy to misjudge—for example, cold oil might appear to be at a high level, but only after the engine runs warm does a low-level issue become apparent. This design ensures accurate readings, preventing issues like foam leakage from overfilling or friction damage from insufficient oil. Remember to always warm up the car, park on level ground, turn off the engine and wait a few minutes, then pull out the dipstick, wipe it clean, and read the warm range. This practice helps prolong the life of your transmission.
