Transmission fluid is a vital component for keeping your car's gearbox running smoothly, whether it's a manual or automatic vehicle. In this step-by-step guide, we'll explain how to check your transmission fluid, helping you ensure safe and efficient driving.

You can find transmission fluid and many other car parts in our store and online.

**What Does Transmission Fluid Do?**
Transmission fluid serves as a lubricant for the various parts and bearings in your vehicle's transmission. Over time, as you use your manual gearbox or automatic transmission, the fluid gradually degrades. This fluid is designed to withstand high temperatures, effectively cooling and protecting the gear system from overheating and excessive friction.

**Are Manual and Automatic Transmission Fluid Different?**
Manual and automatic vehicles both require transmission fluid, but each type of engine needs a specific variant. Using the wrong fluid can lead to lasting damage to the gearbox and its inner components.

- **Manual transmission fluid** (sometimes referred to as manual transmission oil) is darker and much thicker than automatic transmission fluid. It also operates under much higher pressure as it assists a manual gearbox rather than an automatic one.
- **Automatic transmission fluid** is thinner and can come in various colors. It includes a special detergent and anti-foam properties to keep the inner workings of your automatic gearbox clean.

**How to Check Your Transmission Fluid**
To check your automatic transmission fluid, follow these steps:

1. Park your vehicle on a level surface, engage the handbrake, and shift into neutral. Keep the engine running. The engine should be warm for an accurate reading.
2. Open the hood of your car and locate the transmission dipstick handle. Make sure it's the transmission dipstick, not the engine oil dipstick. The handle is usually circular, allowing you to pull it out gently with your thumb and index finger. For in-line engines, the dipstick is usually near the rear of the engine. In front-wheel-drive engines, you'll find it near the front of the engine, close to the transaxle.
3. With the engine still running, remove the dipstick and check that the fluid is nearly clear in color and covers the entire length between the measuring markers. Rub the fluid between your thumb and index finger; it should feel smooth without any deposits.
4. If all checks are correct, clean the dipstick, reinsert it into your vehicle, and repeat the process to ensure consistent results.
5. If you can't locate a dipstick, consult your vehicle's user manual. Some modern cars have a "sealed-for-life" transmission, and the fluid can only be checked by a professional mechanic.

**Signs Your Transmission Fluid Needs Changing**
If your transmission fluid doesn't reach the full length of the dipstick, contains small particles, or has a burnt smell, these are indications that the fluid needs topping up or flushing. Flushing your transmission fluid involves completely replacing the old fluid with a fresh supply.

**How Often Should Transmission Fluid Be Checked?**
It's recommended to check your transmission fluid levels once a month. Additionally, you should change your transmission fluid every six months or after every 30,000 miles.

Regularly checking your transmission fluid is crucial for maintaining optimal performance and ensuring a cool-running vehicle. Just as important as transmission fluid is engine coolant; you can learn more about it in our comprehensive guide on what engine coolant is and how it functions in your vehicle.