Even with a transmission as venerable as the Allison, it responds nicely to some well-placed improvements; that is why PPE has designed the Allison Valve Body Recalibration Kit (VBR kit). This kit corrects the issue with the Allison from going into neutral under a load. It also prevents 3rd to 4th gear slips, C2 or C3 clutch burning, and the tendency of sticking in one gear. This kit allows customers to experience short, crisp and smooth up and down shifts. Kit includes the instructions for a trouble free and worry installation.