MiguelsC2

Are all early muncie 4spd close ratios, M-21s ? And wide ratios, M-20s? Or did both models have close and wide ratios available? I guess I am asking the same question about the later M-22s also?

DZAUTO

I don't know why I'm explaining this for the umpteenth time, I guess I'm just bored.
In the beginning (63) when the Muncie replaced the Borg-Warner T-10, the 4sp transmission option was M20. Period. Depending on engine/rear gear ratio, the car was delivered with either a wide ratio or close ratio Muncie. The option was still M20 for the 4sp.
In 1966, the two ratios were broken down into seperate option codes: M20(wide ratio) and M21(close ratio). The Heavy Duty 4sp transmission was the M22-----------------AND IT WAS CLOSE RATIO ONLY! The M22 was first used in the 65 model year, but such a very small quantity (maybe 20-40 delivered) were delivered that they are ultra rare, and it appears they were only delivered in 396 cars.
The close ratio Muncies have ALWAYS had the 2.20:1 first gear ratio, but the 63-65 and 66-74 wide ratio ratio Muncies had slightly different first gear ratios. The 63-65 had a 2.56:1 first gear ratio and the 66-74 had a 2.52:1 first gear ratio.

Tom Parsons

MiguelsC2

Thanks for the info. Didn't mean to put you out. Since you have been a member here since 2001. I am sure you have had to explain many things, many times over. If you didn't, someone else would.
As long as people are joining the Forum to gather new knowledge "new to them". That's why I joined. Then I am sure the cycle will continue untill there are no new members and everyone knows everything. Then the Forum will have very little purpose. You have to admit the Muncie thing is a bit confusing. I was pretty sure about the M-22. That exsisted in my generation. The others were a bit before my time.

DZAUTO

I forgot to add this.

midyearvette

here ya go!

http://www.5speeds.com/muncie2.htm

MiguelsC2

Thats great info thanks!

1snake

According to that site, all M20's were wide ratio and all M21's were close ratio. That is incorrect.

Jim

Kerrmudgeon

Mike (1sttexan), I've only been a member for a year and can relate to veteran members dealing with same old, same old. It gets kinda boring going over the same damn thing, and that's what the search option of the forum is for. Punch in your key words and see what pops up. Most stuff has been thrashed a lot, so it's on there.
I'd give the same advice to all members, especially new ones......PLEASE SPARE US OLD DOGS, we're looking for new bones to chew. Make our day, challenge our aging minds.Thanks.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

narlee

Tom doesn't really mind. He's one of the best sources of information on the forum.

DZAUTO

What's REALLY important, it that people are still interested enough to ask, rather than just stumble blindly through the night!

Tom Parsons

Mike Terry

It is good to always have new people come into the C1 and C2 Corvette world. It is also good to have people like Tom explain things to them. to Tom

Formula Outlaw

So I have an original 65 L76 coupe. I would think that I would have the close ratio tranny with that engine and 4.11's in the back. What is the easiest way to double check that and please refrain from sending any ICBM's in my direction....

MiguelsC2

Search option doesn't always do it. Or you might have to read multiple threads to get what one properly asked thread will do. It also keeps the current threads lively. Sometimes it gets pretty dead around here.

midyearvette

here ya go again!!

Muncie 4 speed spline, groove and tooth count characteristics.
Type/Year
Input Spline

Input Groove

Input Gear
Tooth Count

Cluster Gear
Tooth Count
Output Spline

Gear Ratio

M20: 1963 - 65 10 none 24 29-22-19-17 27 Note 1
M20: 1966 - 70 10 2 21 25-22-19-17 27 Note 2
M20: 1971 - 74 26 2 21 25-22-19-17 32 Note 2
M21: 1963 - 70 10 1 26 27-22-19-17 27 Note 3
M21: 1971 - 74 26 1 26 27-22-19-17 32 Note 3
M22: 1965 - 70 10 none 26 27-22-19-17 27 Note 3
M22: 1971 - 72 26 none 26 27-22-19-17 32 Note 3

Note 1: M-20 gear ratio: 1st 2.56:1, 2nd 1.91:1, 3rd 1.48:1, 4th direct
Note 2: M-20 gear ratio: 1st 2.52:1, 2nd 1.88:1, 3rd 1.46:1, 4th direct, Rev 2.59:1.
Note 3: M-21/22 gear ratio: 1st 2.20:1, 2nd 1.64:1, 3rd 1.28:1, 4th direct, Rev 2.27:1
Effective October 21, 1968, an additional letter was added to the plant prefix number to help identify the gear ratios in Muncie transmissions. The additional letter codes as follows:
Muncie 3 speed Manual Muncie 4 speed manual transmissions
Suffix 1st gear ratio
A 3.03:1
B 2.42:1

Suffix 1st gear ratio
A 2.52:1 wide range
B 2.20:1 close range
C 2.20:1 Rock Crusher

1snake

Wrong again. It fails to recognize the CLOSE RATIO M20's. Please refer to Tom's post above. Now I know why he gets tired of this crap.

Jim

DZAUTO

10--------9-------8-----7------6------5-------4-------3-------2------1-------LAUNCH!---------------DUCK!

Tom Parsons

DZAUTO

And then there is Gene Holtz in Edmond, OK, who has a 1965 FI car with the ORIGINAL, numbers matching Muncie in the car. The input shaft has 26 splines and 2 grooves around the input splines.
Explain that!
First correct answer gets a gold star!

Tom Parsons

midyearvette

the easiest way to answer that is count rotation of the input shaft vs. the out put shaft on the bench, in all four speeds..if the tranny in question is still in the car, then a close box will drop 5oo rpm in all forward shifts, if it drops more from 3 to 4 shift, it is a wide box.....bwtfdik??.....

midyearvette

im' not here to cause any friction snake, all im doin is posting some results from different web sites and their info....if you guys want to claim they made a close m-20 that's fine with me, if tom says someone has a 26 spline tranny before other knowledge says that spline was released later, then i say amen!!.....because again, wtfdik??...evidentaly not much.....PEACE and good luck........

1snake

If it's original, it will be a close ratio M20 and have the VIN stamped on it.

Jim