Identify 4 Speed GM Transmission

[Warren S.]

Can anyone identify the original usage of this GM 4 speed transmission. Some cast numbers to possibly help identify. Main case #338935 date(?) F-23, Tail Shaft housing #352254 date(?) G215, Side cover #6261886 date(?) 516E.
Any help would be greatly appreciated.
Thanks,
Warren

[Joseph K.]

Re: Identify 4 Speed GM Transmission

If this a muncie, there should be a alpha numeric sequence stamped to the main case on the vertical surface at the front of the right side. One of the sequences is the cars serial number and the other is production code and the date of the transmission was originally assembled. the latter should start with the letter P(Muncie) followed by the last digit of the model year. Next digit would be the month("A" being January) and then the day of the month. the final character is the suffix code A is a M20 B is a M21 and C is a M22
Hope this helps
Joe

[Joseph K.]

Re: Identify 4 Speed GM Transmission

I can't read the numbers on the last photo of your post but the numbers shoud be on that flat spot in the upper right. Let me know what you find.

Joe

[Warren S.]

Re: Identify 4 Speed GM Transmission

Joe, thanks for the quick reply. The case is steel and the stamping on the top right machined verticle surface is 16U139624. I was told that the transmission came out of a 76 Vette, but it doesn't match anything that I've seen for a 76. The reverse lever and the electrical connection coming out of the side cover has me puzzled.

[David D.]

Re: Identify 4 Speed GM Transmission

Looks like a 4 speed Saginaw transmission, with the 3 levers and a TCS switch on the side cover. Probably out of a 1975-1976 Buick Skyhawk or Chevy Monza, Pontiac Sunbird. FWIW

[Joe L.]

Re: Identify 4 Speed GM Transmission

Joe, thanks for the quick reply. The case is steel and the stamping on the top right machined verticle surface is 16U139624. I was told that the transmission came out of a 76 Vette, but it doesn't match anything that I've seen for a 76. The reverse lever and the electrical connection coming out of the side cover has me puzzled.

Warren-----


It definitely did not originally reside in a 1976 Corvette. In fact, it never originally resided in any Corvette. It originally resided in a 1976 GM vehicle that was assembled at an assembly plant identified by the "U" code. I don't know what that was, though.

The transmission is a later, cast iron case "Muncie". This is, basically, the old Saginaw 4 speed after it was modestly revised and manufacturing transferred to the Muncie, IN transmission plant. It was used in many mid-to-late 70's GM vehicles with low-to-moderate horsepower engines, just as the Saginaw 4 speed was used in mid 60's to early 70's such vehicles.

A version of this transmission was used in a Corvette, though. The application was 1978 and, possibly, early 1979 with L-48 engines. Like I say, though, this transmission was not one of those since it was not originally installed in a St. Louis-built vehicle and it's from the 1976 model year when none of these transmissions was installed in a Corvette, anyway.

[Tom R.]

Re: Identify 4 Speed GM Transmission

Joe, thanks for the quick reply. The case is steel and the stamping on the top right machined verticle surface is 16U139624. I was told that the transmission came out of a 76 Vette, but it doesn't match anything that I've seen for a 76. The reverse lever and the electrical connection coming out of the side cover has me puzzled.

I'm with Joe. The late 70's Muncie have three shift shafts out of the cover and the 7 bolt cover. this tranny shows those characteristics but it does differe from the few I've seen.

Warren, in your top set of photos, their is another stamp pad under the cover (bottom side) that can be seen in the photo but has glare. on the 78 Munice, that is the assembly date code. What's stamped there?

[John H.]

Re: Identify 4 Speed GM Transmission

Yup, it's out of a '76 Monza or Vega "H"-body; that's all that was built at Lordstown ("U") in 1976.

[Warren S.]

Re: Identify 4 Speed GM Transmission

Thanks everyone for your input, I was hoping that it would somehow be Corvette related.