monza 4speeds.

[robson]

Looked at the GM heritage site and they showed "78 Monza Spyders 2+2 with factory installed Muncie 4 speeds. My '78 came from the factory with a Saginaw 4speed. Does anyone out there know why the Factory does not state Saginaw 4 speeds came in the Monza Spyders with V8 engines? Thanks Charles.

[Monzamaddogger]

My brother (a former GM transmission tech) told me that at some point GM started calling the Saginaws Muncies.

[cjbiagi]

There was never a "traditional" Muncie installed in Monza's. The power output never required it......

[cammerjeff]

That and the fact that "Muncie" transmission were last made in 1973, the last know one was installed in the 1974 Model year. They were replaced with BW Super T-10's as the supply of that model ran out, M-20 wide ratio, M-21 Close ratio. So by 78 it would have been a ST-10.
But I agree no Muncie or BW ST-10's were installed at the factory in an H-body.

[jpb04619]

i unassembled many hbodies , all standards were saginaws , except one t-50 john b

ps still have 2 saginaws

[Kev442]

I know the transmission factory in Muncie In was open until 2005 or so. My WAG would be that the "saginaw" design was being built in Muncie In and got a muncie code.

[cjbiagi]

That could very well be, for those that don't know, both Muncie and Saginaw are cities in Michigan. So the transmissions obviously got their name from the city they were built in.

[cammerjeff]

That could very well be, for those that don't know, both Muncie and Saginaw are cities in Michigan. So the transmissions obviously got their name from the city they were built in.

Clyde, Saginaw is definatly a City in Michigan (I spent 10 years living there) but I think Muncie is in Indiana about an Hour north on Indy.

I beleive the confusion stems from the option codes Used M-20 was the designation for a 4-speed wide ratio transmission in the 60's and 70's and it depended on aplication and year if a car with aM-20 transmission had a Muncie, Saginaw, or Borg Warner transmission installed in it. But they would all be corectly refered to as a M-20. Even though most hobbiests think Muncie when they hear M-20, M-21, or M-22.

[Monza Harry]

That could very well be, for those that don't know, both Muncie and Saginaw are cities in Michigan. So the transmissions obviously got their name from the city they were built in.

Clyde, Saginaw is definatly a City in Michigan (I spent 10 years living there) but I think Muncie is in Indiana about an Hour north on Indy.

I beleive the confusion stems from the option codes Used M-20 was the designation for a 4-speed wide ratio transmission in the 60's and 70's and it depended on aplication and year if a car with aM-20 transmission had a Muncie, Saginaw, or Borg Warner transmission installed in it. But they would all be corectly refered to as a M-20. Even though most hobbiests think Muncie when they hear M-20, M-21, or M-22.

I would like to add my take as well, I believe the "General" used the "M" to refer to "Manual" at that time, as I remember there being a "T-40" designation for a "Heavy-Duty" automatic trans and the "T" would then mean "Turbo-Hydramatic" Just reading between the lines from a cloudy 40 year old memory! So today the "T" means "Transverse and the "L" designates "longitudinal" Transmission and of course the "E" signifies Electronically shifted/controlled and that there starts the confusion, and then ad's to it, just for their amusement I am sure! Harry

[cjbiagi]

Yep, I stand corrected (again). Muncie is in Indiana.

[Biscayne John]

I beleive the confusion stems from the option codes Used M-20 was the designation for a 4-speed wide ratio transmission in the 60's and 70's and it depended on aplication and year if a car with aM-20 transmission had a Muncie, Saginaw, or Borg Warner transmission installed in it. But they would all be corectly refered to as a M-20. Even though most hobbiests think Muncie when they hear M-20, M-21, or M-22.

And M35 was used for Automatics.

[Biscayne John]

As another note I have a Chevrolet piece of liturature dated 2-74 titled "1974 Cosworth Vega New Product Information Chevrolet Motor Division-Product Assurance" I guess this was an early piece "press kit" I collect as much liturature as I can find on every car I own. I was confused when I purchased my CV becasue in this book it states;

"Transmission

The Cosworth Vega includes a Muncie built 4 speed manual transmission. No other type of transmission is available "

When I looked underneath the car, I never saw a Muncie looking like that one. This piece is a pre-production piece but rather interesting at that.

Now a little history on the GM four speeds and the advent of what is known as the Muncie
Saginaw was a gear plant that goes way back prior to WWII. Steering boxes, three speeds, truck transmissions and even rear end gears were made there also. The early four speeds 58-mid 63 (58 Corvette only) were were built by Borg Warner who was an outside vendor to GM. Those were known as the T-10's, the later issue T-10's known as the Super T-10's were built again built by Borg Warner. Due to the very small numbers of four speeds ordered in the late 50's and early 60's they did not do this in house it was to costly. Strange thing also many of the internals are the same as the early Ford four speed T-10's because they also out sourced four speed production. Which was very unusual for FoMoCo. When Henry was running things he did not like dealing with outside vendors due to experience of having parts held up with strikes at those outside plants, stopping production in the 30's. By the late 50's he was dead and so was his business model.

GM was planning on going away from the outsourcing in with the 1964 model year and move production in house to the Muncie Plant. The change was forced in mid 1963 due to a contract obligation that Borg Warner had with the government to build military transmissions. With the recent Cuban missile crissis and the onset of the Southeast Asian conflict and a rather dated military fleet the government placed a huge order, so Borg Warner had to opt out. Borg Warner still built the overdrive units for the three speed transmissions through the 60's but the numbers on those units are real small, and I think either 66 or 67 was the last year that was offered (not sure I have to check)

I never researched why GM went away from production at Muncie. I do know that GM stated that the Saginaw four speeds were not suitable for use over 300 horsepower which was just about over by 1973 production anyway. I would surmise that the use for the heavy duty box was just needed for production anymore, then factor in the cost of retooling.

[Kev442]

That Borg Warner tidbit goes a long ways toward explaining why Ford toploader three speeds ended up in GM A bodies in the mid to late sixties.