Transfer Case Fluid: How Often & What Is It?

If you aren’t familiar with the term transfer case fluid, do not fret. This article shall be taking you through some very intricate points that concern the transfer case and its fluid. And by the time we are through, you would be well-informed enough to make effective decisions.

A transfer case is a somewhat rectangular box that functions as a component of the drive train (a part of the vehicle that is not the engine but conveys power produced by the engine). It divides the power from the transmittance amongst all four wheels in your vehicle. The transfer case is not found in all vehicles; it is present only in multi-powered axle vehicles like all-wheel and four-wheel-drive vehicles that use both front and back axles.

Transfer cases are also called power take-off units (PTU), and these PTU’s come in different types: the 4WD low, transfer CA’s shift type, housing type, etc.

What is Transfer Case Fluid?

A transfer case refers to one of the components of the drive train in an all-wheel or four-wheel vehicle. As the name suggests, the transfer case is responsible for receiving power from the transmission and transferring it to the (front and rear) wheels, using the drive shafts. It also sends power to the transmission. Essentially, it harmonizes the front and rear wheels with the rotation between them.

The transfer case can be designed from gear or chain drive, so it can be driven by either of the two materials. Depending on the driver, you can convert the transfer case into either four-wheel or two-wheel mode, using the drive.

To control the transfer case, you need an electronic switch. Depending on the type of wheel, the transfer case may be selectable (as in a four-wheel-drive vehicle) or not selectable (as in an all-wheel-drive vehicle).

The power take-off unit fluids eliminate friction while also offering a cooling effect on the case and wet clutch. These functions carried out by the fluid ensure that the transfer case working efficiently with the clutch’s aid determines and send power as needed to the wheels.

Transmission fluid could also be used in place of PTU fluid. Specialized transfer case fluids and thick gear oils could be used as transfer case fluids too.

Does My Car Need Transfer Case Fluid?

The question of whether the transfer case fluid is vital to the engine and the overall performance of the vehicle is a no-brainer. Whether as traditional gear oil or synthetic type, transfer case fluid is essential to some vehicles.

Transfer case fluid helps to remove heat from the transfer case and transmission, thereby reducing friction and lubricating the internal components in the transfer case. It also helps to keep the vehicle cool, allowing the gear to have a smooth turn, and stay in the desired position while engaging easily.

PTU fluid is needed where there is a PTU. So you should first identify whether your vehicle uses a transfer case or not. So, If your vehicle does have a transfer case, then the challenge is easy to resolve.

Just as babies are helpless without their moms, so is your PTU useless without its transfer fluid because even if you attempt driving your car without a transfer case fluid, the case would only get thoroughly destroyed due to overheating and severe friction. Imminently your four-wheel drive would become the latest arrival in scrap town.

How to Replace Transfer Case Fluid?

As it is with many other things on the Earth, transfer case fluids are not eternal. The fluid would lose its lubricating abilities over time due to the breakdown of its composing chemicals. The fluid could also ‘vanish’ away if there is a shaft seal leak in the producing or consuming seals.

The reason for this is that shaft seals are supposed to enclose the PTU fluids in normal conditions. Hence, it would be proper to check and observe the seals for evidence of damage before considering the PTU’s replacement.

Some of the signs that follow a damaged seal include:

A grinding noise from below the vehicle.
The vehicle switches irregularly between two and four-wheel drives.
Problems with changing gears.

After fixing the transmission seal problems, you can then proceed to replace the transfer case fluid. The process involved in replacing a transfer case fluid is easier than crushing on someone, we assure you.

All you have to do is drain the excess fluid by uninstalling the drain plug. After draining is done, reinstall the plug and add the transmission fluid to the required level. You see, it’s easy. If your vehicle doesn’t have a drain plug because the case is completely sealed, suck out the fluid and replace it with a new one.

How Often Should You Change Transfer Case Fluid?

Two things you must ensure while using the transfer case fluid: it should not get contaminated or run low. If you allow this to happen, there is a chance that your vehicle will shudder and cause a failure of the differential.

If you want to prevent this to happen, make sure you replace the transfer case fluid periodically. It is recommended that you should change the fluid every 30,000 miles. This is especially important for tow trucks and four-wheel-drive vehicles. This is because these vehicles use the fluid and make it recycle more frequently.

Period change of transfer case fluid will help reduce the issues related to drivability. Do wait until you drive your vehicle up to 70,000 miles before you replace the transfer case fluid. The consequence of waiting includes inefficient engagement of the car’s drivetrain. This will lead to the overall poor performance of the vehicle.

Final Thoughts

It’s easy to maintain a transfer case fluid. You either have to visit a mechanic to change the fluid regularly before the manufacturer’s stated service time interval or change the transfer fluid yourself.

It would not be best to wait until the transfer case gets damaged before taking action as appropriate.