BD Diesel Shift Kit - Chevy Allison 1000 2006-2008 6spdInstallation recommendation: Experienced technician; Includes our exclusive Smart Trim Clutch Control valve assemblies and items to modify the C2 clutch piston for increased capacity and more durability. The C2 clutch is the weakest part of the early 5 Speed Allison; Addresses goes to neutral under load; 3 4 slip; burned C2 C3 clutches; sticks in one gear; won't move after extended parking; loss of pump prime; smart clutch control valves for increased