If you've ever gotten stuck in your 2017-2023 Ford F-250/350 Super Duty and needed 4-wheel drive, then a transfer case is what helped get you out. It is responsible for transferring power to the front wheels and rear wheels in 4-wheel drive systems. Contained inside the transfer case is a set of gears and chains that are engaged or disengaged depending on the drive mode selected. 4-wheel high is used in high-speed settings such as dirt or snow, whereas 4-wheel low is used in low-speed settings like steep rocky hills where maximum wheel torque is required. Transfers cases typically have two 4-wheel drive settings, a high and low gear ratio for different situations. The Transfer Case mounts to the back of the transmission and is what the front and rear driveshafts connect to.
It is highly recommended to not engage the transfer case for anything other than off-road or low-traction situations. Wheel slip is possible in loose terrain, alleviating any binding that can occur on dry pavement. In some applications, an external brace can be added to increase the structural rigidity of the transfer case to prevent damage from high torque loads or twisting. XDP carries a wide selection of Transfer Case products available from Dorman, Merchant Automotive, PPE, Sun Coast Converters, and more. When you shift the Transfer Case into 4-wheel drive, it locks the front and rear axles together so that they spin at the same speed. Transfer Cases generally are very strong from the factory and do not require internal upgrades unless the vehicle is used for extreme off-roading or racing.