I was approached by a co-worker asking what the system was called that would transfer power from a spinning wheel (on front) to the other wheel. I told him I believed it was the Torsen. So I looked it up and found that Hummer has a 5:1 Torsen and that if one wheel spins free just apply a little brake pressure to put torque to the other tire. Is the Hummer the only vehicle that comes factory with the Torsen? Do the Silverado HD's even have a limited slip on the front? Tell me what an 07 Chevy HD 4x4 front diff has in it from the factory. Will it transfer anything to the other wheel if one wheel has lost traction? If not, what 4x4 trucks will? (from the factory)