The Ford C4 and C6 automatic transmissions have been equipped in millions of production rear-wheel drive cars and trucks since they were introduced in the 1960s (C4 in 1964, C6 in 1966). They remained in production deep into the 1980s, when overdrive-equipped transmissions finally eclipsed them. However, the C4 and C6 remain incredibly popular with enthusiasts, racers, and restorers alike due to their simplicity, strength, and low cost. Rebuilding either of these transmissions isn't overly difficult, but does require care, some specialized tools, and proper procedure to be followed closely. In How to Rebuild and Modify Ford C4 and C6 Automatic Transmissions, author George Reid walks readers through the process step-by-step, from removing the transmission from the vehicle, to complete disassembly and cleaning, to careful reassembly, to proper re-installation and road testing. In addition, if the transmission will be used in a high-performance or competition situation, the author includes the various steps required to bolster the unit's strength, using commonly available aftermarket components. Each chapter contains special notes, sidebars, and technical tips to assist the reader at every step in the process. Some refer to safety, others to time-saving advice, and others to small modifications that may aid long-term durability or help the builder tailor the shift firmness. The author's extensive research and experience with these popular transmissions has resulted in a well-rounded full-color technical guide to their revitalization.