Automatic transmissions are mysterious marvels of the Industrial Revolution. Every mechanical, hydraulic, electrical, vacuum-operated, and electronic component of a modern-day automatic transmission must function in perfect harmony to do its job properly. Like a Swiss watch that keeps perfect time, automatic transmissions are the precision instruments that effortlessly propel many of our custom vintage pickups.

Recently, we heard of a friend's off-road misadventure. While playing in the mud with his son in their '70 Ford Bronco, Steve Shattuck lost the reverse gear in his Ford C4 Cruise-O-Matic automatic trans. We saw Steve's misfortune as a great opportunity to watch how the pros rebuild a C4. By doing so, we could convey the rebuild process and demystify these complex creations of the Industrial Age to CCT's readers via words and photos.

Manufactured 1964 through 1987, Ford's C4 has powered everything from the puny Pinto up to the burly Broncos. Because C4s are compact, well-engineered, and reliable, they back many Ford-powered Ford custom vintage pickups today. Steve selected Westminster Transmission Service (WTS) in Westminster, California, to renew and improve the C4. Owned by Joe Piraino since 1987, Joe and his talented crew have rebuilt GM, Ford, and Chrysler automatic transmissions for street, dragstrip, race, and off-road applications. Indeed, Joe has been working on transmissions at this same shop since 1977. Follow along with us, as Joe and his son Michael, a Mechanical Engineering student at Cal Poly Pomona, rebuild a C4 for off-road fun in a 351W EFI-powered '70 Ford Bronco.