Cognito 210-90468 4 Degree Rear Pinion Angle Shim Kit | 1999-2018 GM Silverado/Sierra 2500HD/3500HD

Features: - Fits 1999–2018 GM 2500HD and 3500HD - Corrects rear pinion angle by 4 degrees - Ideal for short wheelbase lifted trucks - Includes two shims and center pins - Designed for 4–6 inch rear lifts - Helps reduce driveline vibration - Works with spring-only or straight blocks - Simple bolt-on installation to leaf packs - Improves driveshaft alignment and longevity Smooth Out Your Driveline with the Right Angle If you've lifted a short wheelbase Silverado or Sierra and noticed vibration coming from the rear driveline, there's a good chance your pinion angle is off. The Cognito 4 Degree Rear Pinion Angle Shim Kit is made to fix exactly that. Designed for 1999 to 2018 GM 2500HD and 3500HD trucks with a 4- to 6-inch rear lift, this kit is ideal when you're running a spring-only or straight lift block setup that doesn’t include tapered correction. By adjusting the pinion angle by 4 degrees, these shims help align your driveshaft properly, which means smoother operation, less stress on your u-joints, and a more comfortable ride overall. Built for Lifted Trucks That Work Hard This kit includes a pair of heavy-duty steel shims and two center pins to bolt them securely to your leaf packs. It’s a solid solution for single cab or extended cab short-bed trucks where rear geometry changes can be more dramatic with a lift. Installation is straightforward and can usually be done in the driveway with basic tools. Whether you're chasing vibration issues after a recent lift or just looking to get ahead of potential wear and tear on your driveline, this pinion shim kit is a smart upgrade. It’s one of those small but essential pieces that can make a big difference in how your truck performs and feels out on the road or trail. Fits: 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018 GM Silverado/Sierra 2500HD/3500HD