These two production assemblies were the same except for the length of the coupling shaft and corresponding housing. They were a simpler design as compared to the prior assembly used for AA’s with the A-chassis 3-speed transmission. These assemblies may have been replaced due to repairs over the years. Refer to Repair Coupling Shaft for identification.

Assembly AA-4802-B was used for AA131‘s with the 4-speed transmission starting September 1929 through the end of production in December 1932.

Assembly AA-4802-C was used for all AA157‘s which came with the 4-speed transmission as standard.

The housings and the front/rear housing supports were simply coverings to enclose the shaft and retain grease.

The coupling shafts of the assemblies had an integral female gear at the front. This gear meshed with a male gear attached to the 4-speed transmission main shaft with a retainer and conical head locating screw. There was a shaft thrust spring which was centered by the locating screw.

The rear of these coupling shafts had 10 splines which matched the drive shaft splines. Consequently, the new AA-7090-B u-joint had matching splines for the front knuckle.

Refer to the parts table and parts gallery below.

Note – Table part finish codes are found in “Part Description” column following the description. The code meanings are the same as used in the RGJS – (bst)-black satin; (bsg)-black semi-gloss; (bg)-black gloss; (c)-cadmium; (g)-Ford engine green; (r)-raven; (u)-unfinished; (z)-Zink

These assemblies were installed through the rear side of the #3 frame cross member. Consequently, removal required the rear of the AA frame to be blocked up and the rear axle to be disconnected allowing it to be move back enough so that the drive shaft pulled out of the u-joint connected to the rear of the coupling shaft.

Once these tasks were accomplished, the coupling shaft assembly could be disconnected from the transmission and removed through the back side of the #3 frame cross member.

Additional parts not covered by the coupling shaft parts group are shown in the table below. Following the table is a drawing of the installation @ the 4-speed trans.

Note – Some of the Ford drawings show the heads of bolts on the back side of the #3 frame cross member. This makes cotter pin installation/removal difficult. Other drawings show the opposite. This makes cotter pin installation easier. Original Ford assembly line bolt installation direction is not known.