Fits
 Year
Make
Engine
2006-2008
GM
LBZ/LMM w/ 6.6L Duramax & Allison 1000 Trans.
 
The C2 clutch is the weakest part of the early 5-speed Allison, the BD 1604721 Shift Kit addresses this problem by applying BD's exclusive Smart Trim/ Clutch Control Valve assemblies and items to modify the C2 clutch piston for increased capacity and more durability. It also addresses the problems of going to neutral under load, 3-4 slip, burned C2/C3 clutches, sticking in one gear, not being able to move after extending parking, and the loss of pump prime. This kit is capable of handling 500 Street HP.
 
Part Number: 1604721