I have a 1958 fully restored Apache 31. The three-speed (on the column) transmission in my truck is connected to a 235 ci motor and both were in the truck when I bought it unrestored in 1986/1987.
I would like to know if anyone can tell me what transmission I have by looking at the attached photographs.
Last edited by Peggy M; 08/18/20235:14 PM. Reason: added pix with Attach Mgr
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
What you have is the basic standard 3 speed transmission. The official name /number is a Muncie SM 318. It has a non syncro first gear and was used in both cars and trucks with some configuration changes from 55 through 67. Fred
Note: That one appears to have a 64 case according to the date code.
Last edited by rfs56trk; 08/18/20239:12 PM.
1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes 1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes 2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans 1947 Willys CJ2A w/F-Head engine
A Saginaw case is considerably longer, and the side cover has 7 bolts instead of 4. It also has a synchronized 1st. gear. The Saginaw 4 speed uses a very similar case shape, and Reverse is moved to a different shaped rear housing to make room for the 4th. forward speed in the main box. Borg-Warner did something similar back in the 1950's with their T-85 heavy duty 3 speed and the T-10 4 speed. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
As HRL stated 4 bolt side cover units are Muncie's even though some of them were made in the Saganaw plant. The transmission you have is likely from a Nova or Chevelle with the correct truck side cover. A 64-66 truck would have had a short tail housing. (except for overdrive units). GM changed the gear "pitch" in 64 and none of the internal components interchange with the 63 and earlier units. It may be a bit more "heavy duty" than the earlier transmissions as some of the gears are slightly wider. Fred
1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes 1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes 2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans 1947 Willys CJ2A w/F-Head engine
