Last Updated: 07.07.2021

Do you know what helps your 4-wheel drive car get traction when driving off-road, crawling on rocks, or in slippery conditions? Sure, the engine is at the core of this, but another equally important part is the transfer case.

If your car comes with the option of switching between 2-wheel and 4-wheel, the change happens on the transfer case. However, the central role it plays in your vehicle also means it is likely to get damaged faster than other parts. This is why you need to understand the transfer case well and how it functions. 

Keep reading to learn more as we answer the main questions, “What is a transfer case?” and “What does transfer case do?” 

What Is a Transfer Case? 

A transfer case is one of the primary parts of multi-powered axles, such as all-wheel drive and four-wheel drive, found in cars. As the name suggests, a transfer case helps transfer power from a car’s transmission to the rear and front axles through drive shafts.

pull out the transfer case

A transfer case is a device that is positioned between the rear and front differentials and helps connect them through drive shafts to create 2-wheel or 4-wheel drive in a vehicle. If the vehicle is an all-wheel drive (AWD) or 4-wheel drive, the transfer case is used to direct power to two or four wheels. When the transfer case engages the front shafts, the car becomes 4×4 drive because the rear shaft is engaged all the time.

Although all transfer cases have the same operating principle, different vehicle models come with varying setups. Take the example of pickup trucks. Some have four-wheel and two-wheel drive systems, while others come with all-wheel drive options. The all-wheel and 4-wheel drive options provide better maneuverability and traction, which are very important for off-road driving. This is why they are recommended for driving on steep roads, slick tracks, and mountainous terrain. 

What are the Most Common Transfer Case Problems? 

transfer case assembly

For most drivers, the flexibility to shift from 2-wheel drive to 4-wheel drive, especially in rough weather such as a snowstorm, is a luxury that no one wants to forego. Unfortunately, the transfer case does the bulk of the work that can wear it down rapidly if not maintained properly. So, if you do not want your four-wheel drive to fail when needed most, make sure the transfer case is maintained in top condition. 

Here are common signs that indicate your transfer case might have problems: 

Trouble Shifting Gears

If you are having challenges when changing gears, it is the first sign that the transfer case might be having trouble. For example, you might have noticed hesitation when trying to engage some gears. The issue might also be evident only when travelling at some speeds. 

In some instances, the trouble with gears might be caused by a leaking or damaged transfer case seal. Like your car’s transmission, the transfer case operates using a connection of gears and lubricating oil retained with a seal. Unfortunately, the seal of the output shaft becomes weak with time and could compromise the ability to shift gears. To verify if your transfer case has a problem with shaft seals, look for signs of fluid leak under the car. Then, get a mechanic to fix the problem immediately. 

Unusual Grinding Gears 

gap in grinding gears

In a transfer case, the shaft seal does not just help to retain the hydraulic fluid. Furthermore, it seals off the sounds generated by the gears in the case. Therefore, the grinding sound of gears will only be heard when the seal is damaged. These sounds increase with time as the damage continues and the case loses the lubricating fluid

If you notice these sounds, chances are they will be accompanied by leaks, which you can check underneath the car. If these are present, get a mechanic to check both the seal and entire transfer case.

Erratic 4-Wheel Drive Performance 

4-wheel drive systems in vehicles can be active, full-time, or part-time. Active 4-wheel and part-time 4-wheel drive systems allow the car’s transmission to run either in 4-wheel or 2-wheel drive. However, the full-time model means that the car is on 4-wheel drive by default and only shifts to 2-wheel when needed. If you notice the vehicle unusually shifting in and out of the 4-wheel drive, the transfer case is likely having trouble. 

Can You Drive With a Broken Transfer Case?

Sure, you can, but it is a bad idea. Because the transfer case is used to engage the front wheels in a 4-wheel drive car, it implies that you will only be able to use 2-wheel drive when it is damaged. This would be bad news if you were planning for off-road driving or in case of bad weather. Indeed, running a car with a damaged transfer case is not recommended because of the following reasons: 

  • Risk of causing further damage to the transfer case. 
  • Danger of getting stuck in areas that you could otherwise have self-rescued yourself.
  • It is not safe. 

How Can You Avoid Damage to the Transfer Case? 

There are many things, such as poor maintenance and using a lot of power on the highway, that can cause damage to your car’s transfer case and compromise your off-road driving ability. However, you can avoid damage to the transfer case by using the following tips: 

  • Whenever possible, use 2-wheel drive on your vehicle. If the conditions are perfect, such as flat paved roads and dry weather, there is no need to drive on all four wheels. If your car uses all-wheel drive, only use traction control when necessary. 
  • When changing oil, ask your mechanic also to check the state of the transfer case. This can be a great time to identify minor issues and fix them before they can turn into serious problems. 
  • Follow the manufacturer’s manual to ensure the transfer case is repaired on time.
  • If you drive off-road often, ensure the transfer case is checked regularly. 
  • Be gentle when changing gears. 
  • Where possible, try to avoid off-road driving. For example, you can limit rock crawling in the Grand Canyon to once in summer instead of five times a year. 

The tips we have listed will ensure your car’s transfer case is always in top condition. Remember that you should not buy the common argument that “a transfer case is perfectly designed to withstand every off-road driving.” This is a misconception. Like other parts of a car, such as the gearbox and clutch, the transfer case is only able to withstand so much punishment before starting to break down. 

Can You Replace Transfer Case in Your Vehicle? 

Yes, you can replace a damaged transfer case. However, you should start by asking your mechanic whether it is possible to repair it. For example, if the problem is only caused by minor damage to the shaft seals, it is possible to replace them as opposed to going for a new transfer case. 

If you prefer to repair the transfer case, it will be a good idea to go for quality parts, such as those made by respected companies. This will give you the assurance of better performance and longer life. However, replacing the transfer case will be a better idea if the damage is extensive. 

Just like buying spares, you should only go for high-quality transfer cases that are designed for your car model. For example, FEXON 4WD 4-Wheel Drive Transfer Case would be a great find if you drive a Toyota Tundra or Toyota Tacoma. Remember that identifying the right transfer case replacement is only the first step. You also need to ensure it is fitted professionally. 

How Long Do Transfer Cases Last?

One fact about transfer cases is that their replacement can be pretty expensive. This is why it is important to understand how long it will last to prepare for all the associated costs. However, there is no set mileage or time when it comes to the transfer case in your car. 

We have seen transfer cases that have lasted for more than 10,000 miles, while others never passed the 6,000-mile mark. How well you maintain the transfer case and your driving habits will determine the lifespan of the transfer case. Here are some useful points you can use to make the transfer case last longer: 

  • Only buy a high-quality transfer case for your car. 
  • Ensure the device is installed properly by a professional mechanic. 
  • Have the transfer case checked regularly. 
  • Replace the seal immediately if it gets damaged. 
  • Follow the manufacturer’s manual for transfer case maintenance.


What is a transfer case? With the answers we have provided in this post, you now understand the primary role of a car’s transfer case in power transmission. We found it an invaluable component, especially for off-road driving enthusiasts. So, you better take good care of it. 

Remember to also take care of all other parts, including the differential locks, gearbox, engine, and electrical system, because they work together. With a well-maintained car, every ride will be a thriller!

If you have other questions related to transfer cases, leave them in the comments below.