What Is a Transfer Case and How Does it Work?

If you own a vehicle or machine, it’s important to at least have a little bit of knowledge of the parts of the car and what they do. A transfer case is a lesser-known part of the car but it’s still very important that you know what it is and how it works in case for some reason it malfunctions.

A transfer case takes the engine torque and splits it. It takes the power coming from the transmission and delivers it to the shafts that lead to the rear and front axles.

If that sounded confusing to you, don’t worry. This guide will break it down into simple terms and ensure you know how a transfer case works by the end of this article.

What Is a Transfer Case: The Basics

We stated what a transfer case is above. It basically ensures that every part of the vehicle gets an equal amount of engine torque. Exactly how it’s delivered depends on your car and what model it is.

A transfer case is sometimes called a transfer box, but they are the same thing. Most of the time, larger cars have transfer cases including 4×4 trucks or any kind of large truck or machine that you use on a construction site.

The transfer case takes power from the transmission and engine and then divides it and delivers it to the axles.

Some designs of cars take the torque and deliver it to the front shaft by a seat of gears while others deliver the torque with a chain. Most newer cars and models use chains as they are quieter compared to the gears.

For those who like to drive off-road, often prefer a car with gears since they can receive larger amounts of torque without breaking. However, keep in mind that gears cannot stretch like chains so gears can break easily if they are put under too much stress.

In general, though, gears are preferred because they are more durable and have been around for more years so many people find them easier to repair and rely on.

The Speed of Transfer Cases

Most transfer cases are two-speed units. This means they can be set into a lower gear when you want the ratio to be lower from the transmission.

Some machines and cars only have one axle so the engine then only has one driveshaft where it will take the power and deliver it to the axles. When there are multiple axles, the power has to be divided evenly and then sent to each axle individually.

Transfer cases are found in axle vehicles with more than one axle, but they are more commonly found in construction equipment where there are gears and additional torques needed.

In construction equipment, there is usually an upper drive gear followed by a lower drive gear. The center gear is then between the lower and upper gear and allows them to engage with one another.

Parts of a Transfer Case

Transfer cases have many different parts including the housing, the bearings, the gears, the flanges, and the shafts. Most transfer cases also have to have a few other parts to ensure that the case is sealed and that the oil does not leak out.

The O-rings, the seals, and the gaskets also ensure that everything in the case runs smoothly and fits together without making too much noise.

You will find the transfer case behind the transmission and between the axles. It’s connected to all the different axles with a driveshaft.

Has My Transfer Case Gone Bad?

Most of the time, transfer cases do not need a lot of repair work because they are built to last for a long time. However, there are times when it can break and it will need to be repaired right away.

If you do a lot of work in the car that requires the transfer case to work overtime, it’s important to pay attention to signs of failure with the transfer case so you can fix it promptly and easily.

Humming or grinding noises coming from the machine is usually the first sign that the transfer case is failing. You might also experience lurching while you are driving or operating the car or machine.

Sometimes trouble shifting gears also signals a bad transfer case. Fluid can leak from the case which decreases the pressure and it makes it hard to shift to higher or lower gears.

Another common issue with bad transfer cases is that they cannot stay in a four-wheel drive. It may jump in and out of 4WD when there is a broken seal or when the parts inside are starting to wear out.

Another common sign that your transfer case is breaking is that you cannot engage 4WD at all or the 4WD light comes on signaling that there is an issue.

My Transfer Case Has Gone Bad

Transfer cases can be repaired sometimes, but other times, they will need to be replaced completely. Most of the time, you will need to go to a specialized center that focuses only on transfer cases.

If it’s in your truck or car, some regular repair shops can do the job. However, machine transfer cases need to be taken to special shops to ensure the work is done correctly.

Transfer cases are often a more complicated and extensive repair process compared to other parts of machines and cars. This is why you want to make sure you can be an expert as soon as you notice your transfer case is not working the way it used.

Final Thoughts

A transfer case is part of the car in charge of dividing power from the transmission and sending it to the axles. It’s an important part of large trucks and heavy construction equipment.

This is why you need to ensure it’s repaired at a reputable and professional repair shop. The men and women who work at specialized transfer case repair shops have a wealth of knowledge and will ensure your machine and car are taken care of.

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