How to Change Your Car’s Transmission Oil

HOW TO CHANGE YOUR CAR’S TRANSMISSION OIL

Automatic transmission vehicles are incredibly popular because they are very easy to drive and require far less maintenance than manual transmissions. However, this doesn’t mean you can avoid regular automatic transmission servicing.

All cars need maintenance, and in the case of automatic transmissions, this means learning how to change the transmission oil. To help you out, we’ve put together this guide explaining what exactly transmission oil is, why you need to change it, and how to perform a transmission oil change.

Changing the transmission oil yourself can save you money and prevent you from waiting for an appointment with a mechanic. However, it can be a messy and dirty job, so if you have any doubts, always contact a professional transmission specialist.


What is Transmission Oil?

Transmission oil lubricates an automatic transmission so it can perform optimally. It’s very important that your transmission oil is at its required level, otherwise, your transmission can experience significant wear-and-tear. 

Over time, transmission oil can also become dirty or contaminated. Transmission oil performs a secondary purpose of catching impurities and debris that develop due to wear-and-tear. It can help prevent serious problems from occurring to your transmission due to unwanted waste entering the system. 


Why Would You Need to Change Transmission Oil?

To ensure that you stay safe on the road, transmission oil needs to be checked and changed on a regular basis. We recommend that you perform a transmission oil change every 50,000kms. This will help keep your vehicle running optimally and potentially saving you significant money on repairs in the long term. 


Signs That You Might Need to Change Your Transmission Oil

  • Making Loud Grinding Noises:
     If you notice that your transmission is making strange grinding sounds, stop your vehicle and check your transmission oil. If you notice that your transmission oil is at a low level or that the colour of it is brown or black, replace as soon as possible. 
  • Slipping Gears:
    Dirty or low transmission oil can result in a lack of hydraulic power. In order to develop enough pressure to stay in the appropriate gear, a transmission must be clean. When a transmission is too dirty, contaminants can interfere, causing slipping. 
  • Surging of the Vehicle:
    Have you noticed that your vehicle goes backwards for no good reason or suddenly jumps forward? Replacing your transmission oil may help with this issue, however, if problems continue we advise in arranging an inspection with your local transmission expert.
  • Delay in Vehicle Movement:
     Another sign that your vehicle may need its transmission oil changed is a delay in vehicle movement for one or two seconds after being put in gear. 
  • Problems Shifting Gears:
     A car requires clean transmission oil so it can flow easily through the transmission system. A transmission that contains too much debris will cause a sluggish response, resulting in your vehicle changing gears too quickly or too late while driving. 
  • Unpleasant Burning Smell:
    If you happen to smell an unpleasant burning smell coming from your transmission, there’s a strong chance that the transmission oil needs to be changed. If you find that there is burnt fluid in your transmission, this means that there is an issue with the transmission itself. Contact your local transmission specialist today if you notice this in your vehicle.

Checklist of Materials Needed

To perform a transmission oil change, you will need:

  • The owner’s manual for your car
  • The right type and quantity of transmission oil
  • A means of raising your car, such as jack stands or ramps
  • A transmission filter kit – this usually contains a gasket for the oil pan along with a new transmission filter
  • A spanner set or socket set
  • A torque wrench
  • A large drain pan
  • Clean lint-free cloths
  • Plenty of rags to soak up the mess

changing transmission oil


How to Change Transmission Oil

1. Warm up the Transmission

You will be able to drain your transmission oil far easier if it is at operating temperature. Before you begin to change your transmission oil, go for a short drive or run the engine for a few minutes to warm it up. If you choose just to idle the car, make sure you run through all the gear options so the transmission oil has a chance to circulate. Once completed, switch off your engine. 

2. Raise the Vehicle

You need to get underneath your car, so you will have to raise it on ramps or jack stands. It must be level and fully secured in a stable position.

3. Check for Leaks

Once the car is raised, you can visually inspect the transmission to check that there are no leaks. If there are, you will need to consult a transmission specialist who will be able to fix it for you. If not, you can go ahead and perform the transmission oil change.

4. Locate the Drain Plug

On most automatic transmissions, you will be able to find the drain plug easily. On some vehicles, however, you will need to remove the oil pan before you can drain the transmission fluid. Some vehicles might even require you to use a suction pump. It is important to look at the owner’s manual to find out what the procedure should be for your vehicle.

Before removing the drain plug, you should place your large drain pan underneath the transmission to catch the old oil as it drains out.

Once you have found the drain plug, you can usually remove it using a spanner or socket, after removing any guards that may be around it. You need to be careful here as the transmission oil may be extremely hot.

5. Drain the Transmission Oil

Once the drain plug has been removed, the old transmission oil will start to drain into the drain pan. If your vehicle does not have a drain plug, you need to loosen your car’s oil pan instead – remove all but three of the bolts at one end, as this will allow the pan to tilt enough to drain the oil while still remaining in place.

Once all the transmission fluid is drained, you can remove the oil pan completely, ensuring that all the transmission oil is emptied into your drain pan.

6. Examine the Transmission Oil

Once all the oil has been drained, you need to examine the transmission oil and the oil pan to check for any signs of metal debris. There is likely to be a small amount of debris in the old oil, but if you find any large particles of metal, this means damage has been caused to your transmission, so you need to have your car seen by a specialist.

Sometimes damage occurs if your car has been overfilled with transmission oil, so it is extremely important to get the level right when changing the oil.

7. Remove the Old Gasket

The old gasket must be removed gently to avoid causing any damage to the surface. It is advisable not to use any sharp tools here.

8. Clean the Transmission Oil Pan

Before you can add new transmission oil, the oil pan needs to be thoroughly cleaned. Use a clean, lint-free rag to make sure all traces of old oil and debris have been removed.

9. Replace the Transmission Filter

At this point, you will need to remove the transmission filter. If it is made of paper or cotton, you will need to change it. If your filter is metal, you can clean it with solvent and leave it to dry before using it again.

Before replacing or reinstalling your transmission filter, use a clean, dry lint-free cloth to wipe down the transmission and remove any old oil.

If you do need to replace your transmission filter, you need to make sure the new one is positioned in exactly the same place as the old one, and that all the bolts or clips which secure the filter to the transmission are reattached.

10. Install a New Gasket

Your car’s manufacturer may specify a sealant to use when installing a new gasket. It is extremely important to check your manual to make sure you’re using the right sealant.

Once the new gasket has been securely installed, you can reattach the oil pan, making sure you tighten all the bolts to the correct torque.

11. Reinstall the Drain Plug

Before reinstalling the drain plug, wipe it clean with a lint-free cloth. Then install it using a new washer and tighten to the specified torque.

12. Refill With New Transmission Oil

Before refilling your transmission oil, you need to check that you are using the oil specified by the manufacturer. You should then slowly fill your system with fresh oil, making sure you leave time after each pump for the oil to flow in. Keep checking the dipstick as it is extremely important not to overfill. Once the oil reaches the “cold” level on the dipstick, you should stop.

13. Circulate the Oil

Once you have filled the transmission to the correct level, start your engine and move the transmission selector through all the gear options to allow the transmission oil to circulate. Make sure you have your foot on the brake throughout.

14. Perform a Final Level Check

Select the correct gear for checking the level and then give it a final check. Make any necessary adjustments, then you’re done!


Contact the Transmission Experts Today!

Performing a transmission oil change will keep your car running more smoothly and prolong the lifespan of your transmission. However, it isn’t an easy job, so if you don’t feel completely confident, always consult a specialist.

At Automatic Transmissions R Us, we are always happy to help you with all aspects of your automatic transmission. Contact the Auto Trans team today by sending through an enquiry, emailing info@autotransrus.com.au or giving us a call on (08) 9785 0221!