|History of the A-833 Transmission|
The A-833 four-speed was produced from 1964 until roughly 1986. It is noted for its strength and durability. From 1964 until 1972, it was built in two typical mechanical configurations, one with an 18-spline input shaft and the other with a 23-spline input shaft. These shafts are not interchangeable alone. The entire gearset is matched and must be changed as an assembly. Typically, the 23-spline units were installed in small block cars and big block cars up to 426 cubic inches (wedge head in 1965). Later, it was also found behind the 383 and 400 cubic-inch engines. The 18-spline unit is popularly known as the “HEMI” four-speed. These were used in the cars equipped with the 440 cubic inch engine (1966 to 1972) and the famous 426 hemi engine (1964 to 1971). After 1972, the 1:1 final drive ratio gearset was made for another two years, bringing its production run to an end in 1974. However, there was an overdrive unit that was made from the early 1970’s until roughly 1986. This had a final drive ratio of .73:1. During the early years of this run, it was mainly used in A- and F-body cars (Darts, Dusters, etc. and Aspens/Volares). The later years of this production run were installed mainly in trucks.
Over the years, there were several different designs of internal parts, such as synchronizers and gearsets. There are also several different case configurations.
The most obvious visual differences of the A-833 are the overall length, and the output shafts. Early trannys feature a flanged yoke connecting to the driveshaft. Later models had a slip yoke. Chrysler made A-833s in two different lengths over the years, and while the main gear housings were sized the same — and for the most part were the same casting for most models — the tail-shaft housing differed. A- and F-bodied cars received the shorter output shaft and housings, B-, C-, and E-bodies received longer tail-shafts. The flanged ball-and-trunion output shaft was used in 1964 and 1965. In 1966, the slip-yoke output replaced the ball-and-trunion on all A-833s.