2007-2010 Transfer Case Brace 07.5-10 Allison 1000 And 2000 Series 4X4 Transmissions (129020710)Description Cracked transmission tail shaft housings (located between the transfer case and the transmission) are a common problem for GM Allison equipped 4x4 pick ups in off road and drag racing applications. Even a nominal amount of driveline vibration can cause the housing to fail, resulting in a transmission fluid leak or worse; internal transmission and transfer case damage. Once the housing cracks, repairing it requires removal of the