Hello, all. I have a 2003 Silverado 1500 4x4 with the LM7 and 4l60e. The 4l60e is a “four speed overdrive transmission.” However, I have more than four gears. I'll be in the highest gear going up a hill, and it will downshift. But then if I pull the gear selector down into 3, it will downshift again. Does anyone have an idea why? I have been searching for the answer since I got my truck, but no luck. During light acceleration, it shifts into second at 10, third at 20, fourth at 35, but then it goes into an even higher gear the second I hit 40. HELP!