When we first rolled our 2002 Chevy Silverado 2500HD into the bay at PPE Diesel's shop in Montclair, California, we thought for sure the transmission was toast. Interestingly, upon inspection it was ...

When the gods above blessed us with the six-speed T56 gearbox, we were beyond words. Here was this slick-shifting internal-rail gearbox built like a brick poophouse that could handle immense amounts ...

There are few things in the world of high-performance cars that are truly reliable. One would have to be the GM TH400 automatic. As durable as this three-speed juicebox is, there is still room for ...