Do you own a RAV4 and wonder if you need to change the differential fluid or not? Like all other lubricating fluids, the differential oil requires replacement at the appropriate interval.
Differential fluid lubricates the set of gears enclosed in the casing to run smoothly. That will give your car better handling around bends. If your RAV4 is 4WD or AWD, it has an additional component called a transfer case. This also functions as a differential and requires an oil change too.
Read on to find out when to change the differential and transfer case oil!
Table of Contents
- 1 What Is A Differential And A Transfer Case?
- 2 Symptoms Of Low Differential Fluid
- 3 RAV4 Differential Fluid Change Interval
- 4 How Much Does It Cost To Change RAV4 Differential Fluid?
- 5 Recommended Differential Fluid For RAV4
- 6 Is Differential Fluid Same As Transmission Fluid?
- 7 What Happens If You Use Wrong Differential Fluid?
- 8 Conclusion
What Is A Differential And A Transfer Case?
What Is A Differential?
The differential is a set of gears that deliver power from the engine to the wheels on the same axle while allowing them to turn at different speeds. It is a low-maintenance, sealed component that lasts a lifetime if serviced at the appropriate intervals.
Your vehicle has a differential, whether a front, rear, 4WD, or AWD. But how does it work? Let’s first know where you will find this component in your car.
The differential is located alongside the transmission inside a bell-housing in a front-wheel-drive car. For a rear-wheel-drive car, it is between the two rear wheels. The same applies to AWD and 4WD vehicles, but they also have a transfer case.
The differential helps you when you are negotiating a bend. It sends more power to the outside wheel, making it spin faster. That improves handling and cornering. Check out the embedded video for more information on how the differential works.
What Is A Transfer Case?
A transfer case is an integral part of AWD and 4WD vehicles. You will never find it in FWD or RWD vehicles. But what is it, and what does it do?
A transfer case is found between the front and rear axles. That’s the reason why it is sometimes called a center differential. Its purpose is to transfer power from the transmission to the front and rear axles. This component works the same as the differential by appropriately dividing power between the axles to enhance traction.
Some vehicle models have an option to lock the transfer case so that power is distributed equally to the front and rear axles.
Symptoms Of Low Differential Fluid
The differential is a set of gears. These gears are immersed in a differential fluid to reduce friction and make them run smoothly. If you are running low on this fluid, the differential will show symptoms that should tell you when a fluid change is overdue.
The following are the most common symptoms of low or inappropriate differential fluid:
Burning Smell From The Differential
The differential fluid is not the only lubricating fluid in your car. The transmission also has a fluid that can produce a burning smell. So, check it out to confirm that your differential is the culprit.
The smell can be due to high differential fluid temperatures caused by poor lubrication of the rotating components. But it can also come from the leaking fluids if the seals break. Check your car’s parking spot or garage if there are signs of reddish stains on the ground.
You can resolve the problem by replacing the old differential fluid with the recommended type. It may also need gasket or seal replacement if there are leakages.
Whining Noise From The Differential
When your differential becomes noisy, the problem can be a low differential/transmission fluid that can no longer lubricate the moving parts. The grinding gears produce the whining or howling noise you can hear from the cabin. This noise can become louder as you accelerate down the driveway.
Inspect your differential or transmission to identify the culprit and change the fluid. Ignoring the problem can cause more damage.
Vibration In The Cabin
Low differential fluid levels can also trigger vibrations that get transferred to the cabin. Gears grind against each other when there is poor lubrication.
RAV4 Differential Fluid Change Interval
The differential or transfer case fluid breaks down over time and will need replacement. The question is, how often should you do that to be in proper working condition?
Both the differential and the transfer case are sealed components. Fortunately, there is a fill plug that you can remove to inspect the fluid levels and confirm its density.
Visually inspect your RAV4 differential fluid every 15,000 miles or 18 months, whichever comes first. Ensure you have the quantity and density right. If there are visible leakages or a significant color change, you may need to replace it.
When is it time to change your RAV4 differential fluid? We cannot give a straight answer here because it depends on many factors. First of all, you have to know if your model has a rear differential or a front differential.
A rear differential requires a fluid change between 50,000 and 60,000 miles. That, however, depends on the load and driving conditions.
On the other hand, a front differential that shares a housing with a transaxle requires a shorter fluid change interval. Typically, most RAV4 owners do it every 25,000-30,000 miles. But again, you should check with your manual for the recommended intervals.
The differential fluid change interval can be shorter if you use your vehicle for towing. Using a car-top carrier, overloading the vehicle, or frequently driving on an uneven road can cause a faster fluid breakdown. In other words, the harder your car works, the sooner it will require a differential and transfer case fluid change. And you should do that on time to extend the lifespan of these components.
Sometimes you may need to change the differential fluid as soon as you realize the level is low or there are metal fragments in it. That’s why regular visual inspection is recommended.
How Much Does It Cost To Change RAV4 Differential Fluid?
Changing the differential or transfer case fluid in a RAV4 isn’t too expensive for most car owners. You only need to buy the oil and pay the labor cost if you can’t handle it yourself.
Your RAV4 car will require about 0.5-2 quarts of oil, depending on the car year. That will cost you about $30-80 in product and an additional $40-70 for labor. In total, your budget should be around $70-150.
Call your mechanic or take your vehicle to an auto repair shop when it is time for the differential oil change. It is a messy process that requires expertise unless you are an advanced DIYer. But if you still want to go ahead, watch this video on how to do it safely.
Recommended Differential Fluid For RAV4
The differential fluid you should buy for your car depends on the type of differential. A front differential encased in an automatic transaxle requires Toyota Genuine ATF Type T-IV fluid.
A rear differential requires a Toyota Genuine Differential Gear Oil. But if that’s not available, you can use a (Synthetic) Hypoid gear oil API GL-5 with viscosity grades SAE 90 at temperatures above 0°F and SAE 80W or 80W-90 for colder regions. The same fluid for the differential is also recommended for the transfer case. Even if you choose a different oil brand, the viscosity grades should be maintained.
Is Differential Fluid Same As Transmission Fluid?
No. These are two different lubricating fluids formulated for varying purposes. Differential fluids have a higher viscosity, better heat resistance, and handle high pressure better than transmission fluid.
You may hear many people using the two words interchangeably, but that shouldn’t be the case. Even transmission fluids differ depending on the type of transmission system. So, how can they be the same as the differential fluid?
What Happens If You Use Wrong Differential Fluid?
The type of replacement fluid you buy for any car component is crucial. The differential and the transfer case are no different. You should buy the fluid recommended for your car model because the viscosity grade and other properties differ.
Using the wrong differential oil may mean a shorter lifespan or compromised functionality of the components. So, always ensure you choose the correct oil for your RAV4 model.
The differential and transfer case are vital components that enhance cornering and traction for your car. For them to function appropriately and last the lifetime of your RAV4, change the oil at the correct intervals or when necessary. If the fluid change is overdue, you will start noticing warning signs. These include whining noises, burning smells, vibrations in the cabin, and fluid leakages. Always service your car’s differential and transfer case on time to extend their lifespans.