A transfer case is a transmission-based mechanism that allows a vehicle to be driven in two different, forward gears with the same number of forward speeds. The two different, forward gears are called low range and high range. The low range is used for crawling and off-road use, and the high range for highway speeds.
- Part-time 4WD: This type of transfer case allows you to have a four-wheel drive on demand and disengage the system when you don’t need it. It’s designed to be used when there’s plenty of traction, such as when pulling trailers or carrying heavy loads.
- Full-time 4WD: This type of transfer case has all four wheels turning at all times and is not intended for use in dry conditions.
If your vehicle has a part-time 4WD transfer case, it will have an emergency brake lever and be controlled by using your foot to select either high or low range and reverse, park or neutral (drive).
- Active 4WD: A 4WD system that uses a mechanical pump and transfer case as the primary power source for the vehicle’s drivetrain. Active 4WD systems are typically found in higher-end vehicles, including some trucks and SUVs.
Active 4WD systems have their dedicated transmission fluid cooler and cooler lines that run through the transfer case and back to the engine block, keeping them cool during operation. This system also has a dedicated cooling fan that pumps coolant through the system when needed.
- Conventional 4WD – This transfer case is usually found in off-road vehicles, compact trucks, and SUVs with low ground clearance. The main advantage of conventional systems is their simplicity compared to active ones. In addition, they are easier to install and use than active systems in most cases because they do not require additional electronic components or specialised software for operation, although there are some exceptions.
Signs that You Have Problems with Your Transfer Case
- Shifting issues: If you have problems with your transfer case is if it shifts too much or not enough at all. If this occurs, there may be a problem with the rear driveshaft, which connects to the transfer case. If this is the case, then it will need to be replaced. It is also possible that your transfer case may have a bad pinion gear, which meshes with the ring gear of your transmission. This particular transmission component is what guides your vehicle into gear when you press down on the gas pedal.
- Clunking noises when shifting gears: A clunking noise while driving could mean several things: The shifter assembly has worn out and needs replacing, or there is a problem with the linkage between the transmission and the transfer case.
- High oil levels: A high oil level in the transfer case can signify a problem. The most common reason for this is that the transmission has shifted from its normal operating range. If this happens, the transmission will not be able to maintain a constant speed and will slip. This can cause your vehicle to overheat and fail emissions inspections. A low oil level in the transfer case could indicate an issue with your engine oil or lubricant levels. Before continuing your journey, you should have your vehicle serviced if you suspect an issue with your transfer case.
A transfer case, also known as a transfer box or torque converter, is a mechanism that connects the transmission to the driveline. It allows the engine to move from gear to gear but does not allow power to be transmitted directly from engine to wheel.
A transfer case connects the torque converter in the rear axle with the transmission in the front. This allows the vehicle to go from one gear to another without a clutch pedal. Therefore, it ought to be in good condition always.