GM Automatic Overdrive Transmission GD>> Covers 700 R4, 4L60 and 4L60E transmissions. 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