How to Change Rear Differential Fluid: Learn The Basics in This Post

Mar, 2018
How to Change Rear Differential Fluid

All cars have differentials, although their location would depend on the type of the vehicle that you are driving. They can either be in the front or back. For the differentials to maintain their peak performance, it is important that they are lubricated. For this reason, you will need to check the differential fluid from time to time and determine if a replacement is necessary.

If you are interested to learn how to change rear differential fluid, we get you covered in the rest of this guide. We will try to write it in the simplest manner that is possible so that you can easily understand the steps that are involved. Luckily, the task is pretty much easy and can be completed even if you are a car novice.

What You Will Need to Follow this Tutorial

You do not need a lot to complete this task. Basically, here are the materials that you will need in changing the rear differential fluid:

  • Jack stand
  • Ratchet
  • Extension
  • Socket
  • Screwdriver
  • Container
  • Gasket
  • Pliers
  • Plastic scraper
  • RTV silicone
  • Break clean
  • Paper towels
  • Torque wrench
  • Gear oil
  • Pump

Step-by-Step Guide on How to Change Rear Differential Fluid

Ready to change the rear differential fluid? Here are the simple steps that you have to follow:

Replace Rear Differential Fluid


1. Look for the Differential

The first thing that you have to do is to look for the position of the differential in a car. It will be easier to do this if the vehicle is in a ramp so that you will be able to have easy access to what is underneath. If there is no ramp, a jack stand will suffice. See to it that the car is parked on an even surface for your safety.

2. Drain the Oil

Once you have located the differential, the next thing you have to do is to drain the oil that it currently contains. Use the ratchet or the screwdriver to have it open if there is an enclosure. A container should be placed underneath the differential to catch any fluid that will drip from it and allow enough time for the fluid to be completely drained. When you are done, do not just dispose it anywhere. Proper disposal is necessary.

3. Clean the Differential

After draining the differential oil, remove the last screw or bolt from the cover and have it cleaned. Use a brake cleaner to remove dirt on the surface. Wipe it off with a clean cloth until it looks clean. After the cover, clean the surface of the differential using paper towels. Do not use anything that can scratch the surface as it can cause leaks later on. As much as possible, use a plastic scraper.

4. Return the Cover

Once everything has been cleaned, it is now time to return the cover. Before doing so, apply RTC surrounding the edges of the cover. The thickness should be about a quarter of an inch. This step is necessary only if there is no gasket. Wait for 15 minutes to an hour before putting it back in the rear differential. Hand-tighten the screws and use a torque to make it tighter.

5. Fill it with Fluid

After closing the differential, the next thing that you have to do is to fill it with fluid. Open the fill hole of the rear differential and insert a hose. The other end should be in your fluid. Pump the hose and this will start the transfer of the fluid. Wait until liquid drops from the hole, which is an indication that it is now full. Put back the screw and you are now done.

Watch the short video below and see how to complete the steps that have been mentioned above:

Pro Tips

After discussing the steps, this section will be focused in providing some tips about rear differential oil.

When to Replace Rear Differential Fluid

In most cases, it is recommended that the rear differential fluid should be replaced after running for 30,000 to 60,000 miles. However, this can be dependent on the number of factors. To be sure, the best thing that you can do is to consult with the manual and do exactly as it has been recommended by the manufacturer of your vehicle.

When it is time to replace the different oil, make sure that you do not mix different types. This is also the reason why you have to start by draining the old oil. Mixing two types can result in a problem and can compromise the performance of your car.

Choosing a Rear Differential Fluid

Now that you have decided that there is indeed a need to change the old differential fluid, your next concern is most probably which one is the best.

Among others, one factor that you have to consider is viscosity, which is recognized as the most important quality of any lubricant. Higher viscosity is generally better, which would also mean that the fluid is thicker. This means that the oil will be able to withstand even extremely hot temperature.

If possible, look for a more expensive brand. This would mean spending more money, but generally speaking, this is also tantamount to having better quality.

It will be a good idea to read online reviews and ask experts in car repair and maintenance. They can provide you with valuable advice on which oil is best for your needs.

Other Tips to Keep in Mind

Aside from knowing when to replace and how to choose a rear differential oil, these are other important tips to keep in mind;

  • Be careful when draining and pumping gear oil. It can have foul smell that will be reminiscent of rotten egg. Wear protective clothing. If the differential is in the glovebox, cover the floor to be sure that oil will not reach the surface.
  • Do not go beyond the recommendations of the manufacturer when it comes to when the rear differential fluid should be changed. Otherwise, it cam create friction and heat, which will both speed up wear and tear of the different components.
  • The rear differential oil can also be hot. Allow the car to cool down before you work. Wear protective clothing and gloves. Also, have a container to catch the oil.


In sum, learning how to change rear differential fluid can be a huge money-saver since you no longer need to pay the pros to do the job. This is one routine maintenance that every car owner should learn. As shown in the discussions above, the task is pretty much easy and can be done without the need for expensive tools.