What is an M20 Muncie 4 speed?
What is an M20 Muncie 4 speed?
The Muncie M20 is basically a wide-ratio transmission and was intended for normal street driving use. The early ones had a 2.56:1 first gear. The later 1966-1974 units had a 2.52:1 first gear. They are compatible with a GM 3 Series differential.
Is a Muncie M20 a good transmission?
GM’s goal with the Muncie four-speed was to produce a better shift employing larger synchro cones. He tells us both the M20 wide-ratio and M21 close-ratio transmissions were first offered in 1963….21.
| Muncie Four-Speed Gear Ratios | |
|---|---|
| M20 Wide-Ratio 1963-’65 | |
| M20 Wide-Ratio 1966-’74 | |
| First Gear | 2.52:1 |
| Second Gear | 1.88:1 |
What is the gear ratio on a M20 Muncie?
2.56:1 ratio
The 2.20:1 ratio first gear is usually referred to as the Muncie M21 transmission; based on GM’s production codes. The 2.56:1 ratio is referred to as the M20.
How much is a Muncie 4 speed worth?
Muncie 4 Speed M20 or M21. $2899.99 OR WITH Muncie CORE exchange $2499.99.
How much torque can a Muncie M20 handle?
The muncies have better cases & handle up to 500-600 lbs-ft of torque. I know my muncie m20 & my friend’s m20 handle our cars at over 500 lbs-ft of torque.
How do I identify my Muncie M20?
Vehicle Identification Number Stamped Into The Main Case Another way to confirm that the transmission is original to your car is most Muncie four-speed transmissions will have a Vehicle Identification Number (VIN) number stamped on the main case.
What’s the difference between M20 M21 or M22 transmission?
The M20 and M21 transmissions produced from 1963-’74 are easy to identify in both wide- and close-ratio units. The M22 to come later in 1967-’74 is also a close-ratio unit, but much stronger than the M21, with a higher torque capacity.
What is the difference between M20 and M21?
Getting back to the HQ type M20 (6cyl & 253 V8 only) its 1st gear ratio is 3.07, the M21 (308 & 253 only) has a 1st gear ratio of 2.54. The M22 (6cyl One Tonners only) has a 1st gear ratio of 3.74. These boxes carry thru to the VK Commodre (M22 finished with the WB One Tonner).
Why is the M22 called rock crusher?
M22 gears are also made of a higher-grade nickel alloy. The M20 and M21 cluster gears are cut at a 45-degree angle. The reduced gear angle of the M22 created a problem with noise (hence the name “rock-crusher”).
What cars came with a Muncie 4-speed?
10-spline units came in these vehicles: 1964-70 Chevy Corvettes and Pontiac Tempest 1967-70 Buick Special, Firebird and Camaro 1969-70 Grand Prix 1963-69 Impala 1965-70 Nova and Olds Cutlass/F-85 and Chevelle (except 1970 w/454-cu.in.
Why is the Muncie M22 called the rock crusher?
How much torque can a Muncie m20 handle?
What is the difference between Muncie M22 and M21?
The M22 to come later in 1967-’74 is also a close-ratio unit, but much stronger than the M21, with a higher torque capacity. Because the Muncie has so much in common with the T-10 and even similar Saginaw boxes, it is easy to get this guy mixed up with non-Muncie units.
Why is the Muncie 4 speed called the rock crusher?
The M20 and M21 cluster gears are cut at a 45-degree angle. The reduced gear angle of the M22 created a problem with noise (hence the name “rock-crusher”).
What is the difference between a Muncie M21 and M22?
Why is M22 called rock crusher?
What cars came with M22 rock crusher?
From 1965-onwards the Rock Crusher was available with the Corvette, and by 1969 it was found on vehicles as diverse as the Chevelle, the Camaro, and the Oldsmobile 442. If a car made big power, chances are a Muncie M22 was on the menu.
