2001-2007 LB7/LLY/LBZ Duramax Allison Transfer Case Braces have been developed and tested for use on high horsepower Duramax applications, adding significant strength and reducing driveline flex common to extreme use such as off-roading, pulling, and drag racing. Helps eliminate the possibility of a cracked transmission tail housing on your Allison transmission from driveline vibrations due to things like a damaged u-joint or driveshaft by spreading the transfer case load across the transmission center section.