NP261XHD OEM Quality Replacement Transfer Case Remanufactured By Transfer Case World in the USA!! 18 Month Unlimited Mileage Replacement Warranty! Fits Chevy & GMC 2500HD/3500HD Trucks w/ 6.6L & 8.1L Engines Check Fitment Guide BEFORE ORDERING! (Verify You're Ordering The Correct Unit) The NP261XHD rebuilt transfer case from Transfer Case World is engineered for strength and dependability. This OEM-grade unit is a direct-fit replacement for 2001–2007 Chevy and GMC 2500HD/3500HD trucks equipped with the 6.6L Duramax or 8.1L Vortec engines and manual shift transfer case (RPO Code NP2). This heavy-duty model features a 29-spline input shaft compatible with both the Allison 1000 automatic and ZF6 manual transmissions. Built in-house by our team of expert builders, every NP261XHD undergoes rigorous testing — including spin balancing, leak detection, and shift simulation — to ensure it's ready for install and built to outlast. We’ve addressed known factory weak points by including our upgraded aluminum rear case half, solving the infamous “pump rub” oil loss issue permanently.