If you've ever gotten stuck in your 2007.5-2018 Dodge Ram 2500/3500 and needed 4-wheel drive, then a transfer case is what helped get you out. 4-wheel low is for low-speed situations where maximum torque is required such as driving up a steep rocky hill or pulling out a stuck vehicle. The Transfer Case mounts to the back of the transmission and is what the front and rear drive shafts connect to. The transfer case in a 4-wheel drive system is responsible for transferring power to both the front and rear axles. Transfers cases typically have two 4-wheel drive settings, a high and low gear ratio for different situations. There are usually two different gear ratio options with a Transfer Case, 4-wheel low and 4-wheel high.
It is highly recommended to not engage the transfer case for anything other than off-road or low-traction situations. Since transfer cases lock the front and rear axle together, the wheels are unable to spin at different speeds making turning and cornering on dry pavement difficult. A Transfer Case typically does not require internal upgrades or modification unless the vehicle will be used for extreme off-roading or racing applications. 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. Shop XDP's large selection of Transfer Case products from the top brands such as Merchant Automotive, PPE, Sun Coast Converters, and Dorman. When engaged in 4-wheel drive the transfer case and drivetrain need some wheel slip to prevent binding or damage.