A904 / TF6 / 30RH / A998 / A999 / 31RH / 32RH

A904 / TF6 / 30RH / A998 / A999 / 31RH / 32RH

A904, 30RH, TF6 - The 3-speed gearbox was released on the market in the 1950s and was produced until the 1990s, although in later years its design was also used in modern truck gearboxes. Some modifications of this gearbox had lockup clutches. The A904 has many variations and many parts are not interchangeable.

A904 / TF6 / 30RH

A998, A999 - The 3-speed gearbox is very similar to the A904 gearbox. It has 5 "Direct" friction discs. Like the A904, it has low gearing in first and second gears, which helps increase acceleration without sacrificing highway fuel economy for small-displacement engines.

A998 / A999 / 31RH / 32RH