Trying to help my friend ID the transmission in his 1955 first series 3104 pickup. So far everything looks correct but this trans looks wrong to me. I haven't had a 3 speed in a long time, and what I had was a 54 that had a torque tube. I know that my tailshaft housing was completely different. Much shorter. I was under the impression, that as the y 55.1 supplement states, that the 54 trans was only modified to be able to use the hotchkiss type u-joint. This trans looks like it would be of a later type.
The case casting number is 3845122, and the tailshaft housing number is 3707196 if I'm reading them right.
1955.1 Chevrolet 3600 NAPCO 4x4 #1 1955.1 Chevrolet 3600 NAPCO 4x4 #2 1954 Chevrolet 3600 pickup 1956 GMC 100 NAPCO 4x4
As per parts book casting # for 1949-1954 (1/2 ton) is 591615. For 1955-1959 with out overdrive is 3845122. Does not mention 1st design 1955 so I would assume 1st and 2nd all used the 122 - which also fits the 55-57 passenger car with overdive,55-57 truck also used. There would be differences in the casting such as holes drilled and tapped or no holes. 3707195 is shown as casting numbers for extension for 1955-1959 truck with out overdrine.
I will admit to reading more than just this forum on old Chevrolets. :-) But I only participate on this one. The reason for that being that I've found the answers given here to be the most accurate, as for example, the answer you got above. Hope you enjoy being here as much as I do!
. Napco was a Silver Book option. In 1937, you could order an Asam 4 WD for extra traction. Web page: <http://home.znet.com/t1937/4WD.htm> . Note that there are no U-joints in the Asam drive line. Many other outside manufacturers have made 4WD Chevys over the years. . .
