on shift linkage side: 3845157
on opposite side : GM 13 3845122 E247
on tail cone: GM 27 E247# 8707185
(# missing number due to rust build up)
To give you a brief overview.
All transmissions have an assembly date code stamped on the main case. There are also casting numbers on individual parts that make up the entire transmission. Car & truck saginaw transmissions often have different date code stamping locations. Assembly date code reflects model year of stamping, not calender year.
3 speed transmission in 1955 was a saginaw design. The transmission is side loaded with a side lever shift & found in all early 3 speed applications. Features include a three step countershaft cluster with the small step in the centre, & a clutch style synchronizer externally splined for the first & reverse shift gear. Not easily distinguished from the 1964 & later saginaws but slightly smaller & has different gear helix angles. Externally this transmission can be identified by the 4 bolt side cover and the elongated tailhousing. One draw back is that the trans is not fully synchronized which led to a new saginaw design in 1966.
Date Coding
All 55 to 59 three speed have an assembly date located on the right hand side of the main case flandge where the tail housing bolts to the main case.
This stamping is unlike the casting number which is raised off the surface of the individual part.
This stamping is usually alpha code indicating the source of the trans followed by several numbers indicating specific month & day the trans was assembled.
Saginaw 3 speeds were built in both Saginaw, Michigan & Munchie, Indiana.
A typical Saginaw assembly date stamp would be S313 indicating Saginaw trans produced March 13. There is not a year identification in the assembly code. You must refer to the casting dates of the particular case to discover the year of manufacture remembering that the casting date must alway precede the assembly date.
Saginaw Maincase I.D.
The 55 three speed main case is casting #3845122 used through the 1957 for both passenger & corvette models.
The #3743368 maincase was used in most 1958 with some applications into the 1963 model years.
All maincases were manufactured out of cast iron.
SaginawTailhousing I.D.
Several extensions used during 55 to 59 model years. The primary difference was tied to model usuage.
1955 to 1959 passenger tailhousing casting #3707195
Corvette #3722946.
The 1957 to 1960 corvette #3737450 then changed to #3722946 with addition of venting assenbly.
Saginaw Sidecover I.D.
There were 4 different sidecovers used from 1955 to 1959.
The differences in the grooved shafts that protrude through the side cover are the best indicators as to wether the trans is for a passenger car or corvette.
On corvettes the shaft groovesare at the top with the shaft in the mounted position, which causes the shift levers to point upwards. On passenger cars the levers point to the side or downward depending on the particular car application.
These are the numbers 1955 two designs #3845044 & #3845157.
In 1956 #3845157 for both passenger & corvettes.
In 1957 two designs #3741357 for passenger cars #3731911 for corvettes.
This was maintained through the 1963 year.
:anim_25:
can help me out with out starting a new thread. I have a 56 belair but it appears to have a 283 corvette engine in it and a three speed manual tranny. I'm trying to identify the tranny so I can order some parts for it. According to the quoted section above my side plate has the same numbers as the 1955 Saginaw- 3845044.
