2001-2004 GM NP261XHD & NP263XHD Transfer Case
A Transfer Case is a fundamental part of the 4WD drive system on your 2001-2004 Chevy Silverado or GMC Sierra 2500HD/3500HD. The LB7 Duramax trucks came equipped from the factory with either a New Process NP261HXD transfer case or NP263HXD transfer case (also known as a New Venture NV261 / NV263 or GM 261XHD / GM 263XHD). Bolted to the back of the transmission, a transfer case has two driveshafts connected to it that run to each axle. It is responsible for transferring power to the front wheels and rear wheels in 4-wheel drive systems. 4-wheel high will maintain the same gear ratio as 2-wheel drive and is for high-speed situations such as driving on dirt or snow-covered roads. Contained inside the transfercase is a set of gears and chains that are engaged or disengaged depending on the drive mode selected. 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 LB7 Duramax Transfer Case is designed to be used in off-road or low-traction situations and is not recommended to be used on dry pavement where wheel slip is not possible. Wheel slip is possible in loose terrain, alleviating any binding that can occur on dry pavement. 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. Transfer Cases generally are very strong from the factory and do not require internal upgrade unless the vehicle is used for extreme off-roading or racing. External upgrades such as transfer case braces are offered for certain applications that add structural rigidity to prevent damage from high torque loads and twisting. Shop XDP's large selection of Duramax LB7 Transfer Case products from
the top brands such as Merchant Automotive, PPE, Sun Coast Converters,
Dorman, and Zumbrota Drivetrain.