What is it?

In a four-wheel drive vehicle, the transfer case is the central component of the driveline that sends power to the front and rear axles. It is typically located at the rear of the engine, just behind the transmission.

What does it do?

The front and rear axles each have their own driveshaft, and the transfer case splits the engine’s power between them. It does this by using a set of gears, chains, or belts to couple the front and rear driveshafts to the main shaft from the transmission. The transfer case also usually houses the differential gears for the front and rear axles. Some transfer cases also have low range gearing that can be engaged to provide extra torque for off-road driving or towing.

Typical Wear and Tear

Over time, the transfer case can suffer from wear and tear due to heavy use. The most common problem is a leak in the seals or gaskets, which can cause the fluid to leak out. This can lead to damage to the gears and bearings, and it can eventually cause the transfer case to fail. Other common problems include broken or damaged shift forks, worn synchronizers, and stripped gears.

Symptoms

• Grinding noise
• Difficulty engaging or disengaging the four-wheel drive system
• Slipping out of gear frequently
• Vehicle vibrates in four-wheel drive mode