To keep your car gearbox running smoothly, transmission fluid is an essential component in every manual and automatic vehicle.
In this step-by-step guide, we will explain how to check your transmission fluid, allowing you to drive safely on the roads. Transmission fluid is one of hundreds of car parts available from us, in store and online.
What Does Transmission Fluid Do?
Transmission fluid is a substance that lubricates the parts and bearings of your vehicle’s transmission. When using your manual gearbox or automatic transmission, the fluid gradually wears away. Because of this, transmission fluid is made to cope with hot temperatures, which then cools and protects the gear system from overheating or unnecessary friction.
Are Manual And Automatic Transmission Fluid Different?
While both manual and automatic vehicles use transmission fluid, each style of engine needs a specific type. If you put the wrong fluid into your car, this can cause lasting damage to the gearbox and inner workings.
Manual transmission fluid (sometimes called manual transmission oil) is darker and much thicker than automatic transmission fluid. It also must work under much heavier pressure than automatic transmission oil, as it is assisting a manual gearbox to run, rather than an automatic one.
Automatic transmission fluid is thinner in consistency and can come in an assortment of colours. Along with helping your automatic car to run, this fluid has a special detergent within it, as well as 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 you need to:
- Park on a level road or surface and lift your handbrake. Put the car into neutral and keep the car engine running. You need the engine to be warm to check the automatic transmission fluid levels.
- Next, lift your car bonnet up and find the dipstick handle which is sticking out of your transmission. Ensure it is the transmission dipstick and not the engine oil one. The handle will be circular allowing you to pull it out gently with your index finger and thumb. If you have an in-line engine, the dipstick will be near the rear of the engine. If you have a front wheel drive engine, the dipstick can usually be found close to the front of the engine, by the transaxle.
- With the engine still running, take out the dipstick and check that the fluid is almost clear in colour and runs the full length of the measuring markers. Also, rub the fluid on the dipstick between your index finger and thumb; it should feel smooth without any deposits in it.
- If all these checks are correct, clean the dipstick before returning it to your vehicle and repeat the process one more time, to ensure you get the same results
If you can’t find a dipstick, check your vehicle user manual, as some modern cars do not have dipsticks; they instead have a ‘sealed-for-life’ transmission. This means the only way you can check the transmission fluid is by going to a professional mechanic.
Signs Your Transmission Fluid Needs Changing
If your transmission fluid doesn’t cover the full length of the dipstick, it looks to have small fragments in the fluid, or it smells like it’s burnt, these are signs that the fluid either needs topping up or flushing. Flushing your transmission fluid completely clears your vehicle of your old fluid, before a new supply is added
How Often Should Transmission Fluid Be Checked
It is recommended you check your transmission fluid levels once every month. It is also recommended you change the transmission fluid in your vehicle every six months, or after every 30,000 miles.
Checking your transmission fluid is vital for making sure your car keeps cool. Engine coolant is another key factor in ensuring a steady and smooth drive. To find out more, read our full guide on what engine coolant is and how it works within your vehicle.
