Chrysler Transmission Options

This information is a sincere effort to impart a basic understanding of automobile technology. If, while attempting to apply any of the ideas, procedures or suggestions herein, you should experience any kind of automobile system failure, it will be as a result of your own conscious decision and actions. All authors of text found here, or anywhere on this site, disclaim responsibility for any reader's actions, and any damage, injury, or death that occured or may occur based on information found herein. Before proceeding, please read our disclaimer.

A discussion of A-body transmission options doesn't need to be limited to the OEM transmissions for any particular year, but can incorporate discussions of B/C-body transmissions as were late-model five speed options. For this reason, almost all 1960-1980 tranmission options are discussed with a focus on A-bodies, however before spliting into discussions of automatic or manual transmissions, the commonalities of the two should be covered briefly.

Not all Mopar transmissions are the same length. Excluding 4wd truck and some van "shorty" transmissions, the world of Chrysler passenger car transmissions can be divided into the ranks of "long tailshaft" and "short tailshaft" transmissions. Automatics are simple, A-727s are long tailshaft and A-904s are short tailshaft. For manual transmissions, some further defining is required. All A-body and F-body manual transmissions are short tailshaft transmissions. All B-body, C-body, and E-body transmissions are long tailshaft transmissions.

In addition to a length issue, for each of the three families of engines Chrysler produced, there were three seperate bellhousing bolt patterns. G/RG family engines (170/198/255 slant sixes) used one pattern, A/LA engines (273/318/340/360 small blocks) used another pattern, and B/RB engines (361/383/400/413/426/440) used yet another. Some truck bellhousings were built to accept multiple engine applications, but for the most part Chrysler built different bellhousings for different engines.

Automatics

All A-body automatics were 904s until 1967, when the transmission tunnel was enlarged enough to make room for the bulkier 727 case. 727 A-body applications were primarily limited to high performance and heavy duty applications, like 340 cars and taxis. The 904 carried on as the most common transmission in A-bodies. Besides case size, 904s and 727s used different torque converters and these do not interchange.

the major external difference in identifying
904s and 727s is the shape of the pan.

On all 1964 & later 904 automatics, an internal ATF filter was used. 1963 904's used an external filter that was installed inline with one of the trans cooler lines.

In 1965, Chrysler abandoned the pushbutton transmission control in favor of a column shift control. This column shift control required a rather unique box at the base of the steering column that operated the two cables. Cars that had center consoles and floor mounted gear selectors for 1965 used a special shifter that operated the cables.

In 1966, Chrysler began using "lever shift" versions of both the 904 and the 727 automatics. For these units, rod linkage (either from a console or a column) moves a lever through the 6 detent gear positions on the transmission.

1965 was the year that Chrysler phased out the ball-n-trunion driveshaft in favor of a slip yoke with a cross-n-roller U-joint. For the most part, B-body and C-body 727s were slip yoke in 1965, and A-body 904s were mostly ball-n-trunion. Since it was a transition year, both style transmissions can be found in A, B, and C bodied automatics. Almost the entire lot of 1965 A833's were ball-n-trunion, for A, B, and C body cars. Ball-n-trunions, if serviced, will last forever (make sure the dust boot isn't broken).

66 & later transmissions began using a different torque converter which only fits 66 & later transmissions, making the 65 & earlier torque converters unique. In 66, the converter was changed to directly drive the fluid pump at the front of the transmission.

For six cylinders, 1968 slant six and small block engines began using a larger counterbore in the crankshaft and a larger torque converter snout. The newer diameter is 1/4" larger. 1968 & later torque converters can not be used will 1967 & earlier cranks for this reason. The opposite scenario, a 1968 and larger crank with a 1967 & earlier torque converter, is possible. An adapter ring must be fitted to the counterbore on the later crank so that the converter snout fits snuggly in the counterbore.

the flex plate center register was larger on 68 & later units as well. When swapping transmissions, the flex plate should match the crank (if its a 68 & later crank, use a 68 & later flexplate!). The same applies to flywheels! 1967 and earlier flywheels had a smaller center hole than 1968 and later flywheels.