Muncie close ratio vs wide
#1
Le Mans Master
Thread Starter
Muncie close ratio vs wide
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?
Last edited by MiguelsC2; 03-21-2010 at 04:09 PM.
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Gettysburg (04-16-2017)
#2
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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
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
Last edited by DZAUTO; 03-21-2010 at 05:05 PM.
#3
Le Mans Master
Thread Starter
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
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
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.
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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.
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.
#5
Le Mans Master
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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.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Last edited by Kerrmudgeon; 03-22-2010 at 01:07 AM.
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What's REALLY important, it that people are still interested enough to ask, rather than just stumble blindly through the night!
Tom Parsons
Tom Parsons
#11
Le Mans Master
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
#12
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....
#13
Le Mans Master
Thread Starter
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.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
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OldCorvetter (05-22-2020)
#14
Le Mans Master
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
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
#16
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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
Explain that!
First correct answer gets a gold star!
Tom Parsons
#18
Le Mans Master
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??.....
#19
Le Mans Master
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........