Is there a hard shift on a GM Truck?
Is there a hard shift on a GM Truck? From buying research to owner support, join 1.5 MILLION GM Truck Enthusiasts every month who use GM-Trucks.com as a daily part of their ownership experience. Anyone else experiencing a hard shift or hesitation of the engine when you first hit the gas. What causes hard shifting on a Silverado 1500? A P1870 code (trans slippage) for instance will command max line pressure causing the hard shifts. You can get that code with bad fluids and filter or with something major going bad inside the trans. I can't remember if this code...