There's an important component standing between your engine and your drive wheels: the transmission. Inside that metal case is a bewildering array of gears, bearings, seals, and more. The automatic transmission is a miracle of modern engineering, but it can also be a source of trouble. If your transmission breaks down you're not going anywhere, and if it's just not working properly, your car will never realize its performance potential.

In this book, expert mechanic and drag racer Cliff Ruggles demystifies the popular GM 700-R4 and 4L60 automatic transmissions. Keeping the enthusiast in...