rotorwrench
Well-known member
A lot of folks refer to them as the X series due to the Ford references. Ford-O-Matics are old school and are, for all intents & purposes, still a two speed with a manual helper gear. The medium case Cruise-O-Matic used from 1958 through the early to mid 60s was a better unit with full dual range 3-speed function and vacuum modulation in later units but they are still weak in the case area and can be damaged under hard use. They can be quirky too. They don't shift real well until they are fully warmed up. The FMX that came out in the later 60s has a beefier case with better web structure. Their not as quirky either and will shift fairly well when cold but they still aren't as beefy as the Ford C6. Now the AOD went a step further in strength but still uses X series design features in the way it functions as a 3-speed with 4th OD. The locking clutch feature is also a very good thing. These transmissions can take a lot more than any of the old X series but they don't have a removable bell so adapters have to be made. The adapter set up gives a much better starter to the old Y-block. Those old starters were a PITA.