Table of Contents
What are the gear ratios in a Muncie M20?
Guide to Muncie M20, M21, and M22 Four-Speed Transmissions
| Muncie Four-Speed Gear Ratios | |
|---|---|
| M20 Wide-Ratio 1963-’65 | |
| First Gear | 2.56:1 |
| Second Gear | 1.91:1 |
| Third Gear | 1.48:1 |
How much is a Muncie M20 worth?
Muncie 4 Speed M20 or M21. $2899.99 OR WITH Muncie CORE exchange $2499.99. If you have no useable core the price is $2899.99!!
How do I identify a Muncie M20 transmission?
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. The engine and transmission were stamped at the same time by the final assembly plant.
Why is the M22 called rock crusher?
The reduced gear angle of the M22 created a problem with noise (hence the name “rock-crusher”). Performance seekers decided to live with the noise when the benefits of increased durability from the gear-tooth angle outweighed the gravelly clatter.
What’s the difference between a Muncie M20 and a Muncie M21?
The Muncie M20 is basically a wide-ratio transmission and was intended for normal street driving use. They are for economy and street drivability and just cruising. The Muncie M21 is a close-ratio unit originally designed to be matched with 4.11:1 or 4.56:1 GM 4 Series differentials.
What transmission is the rock crusher?
The 2.56:1 ratio is commonly referred to as the M20. Muncie also had a second close-ratio transmission designated M22 and often referred to as the “rock-crusher,” which was used behind the highest-performance engines and in Corvettes, the M22 is a highly sought-after performance transmission.
Are Muncie transmissions still made?
In 1990, General Motors combined Muncie transmission operation with Chrysler Corporation’s New Process Gear creating New Venture Gear, Inc. The partnership later dissolved and the company once known as Chevrolet-Muncie closed its doors on March 31, 2006.
Are all Muncie transmissions aluminum?
These early units went through design changes in their youth, and the 1963-65 units, because of the smaller input shaft, are not the best transmissions to use in a swap, but it is possible. All Muncie transmission cases are made of aluminum, which helps in identifying it as well.
What is Rock Crusher transmission?
An M-22 “Rock Crusher” is a Muncie four-speed transmission for cars made by General Motors in the 1960s. You can identify several unique signs that identify an M-22 “Rock Crusher,” even if it does not have a GM hallmark imprinted on its surface.
Who made Muncie transmissions?
General Motors
The Muncie SM465 is a heavy-duty, four-speed manual transmission built by General Motors for use in light and medium duty trucks from 1968 to 1991 at the factory in Muncie, Indiana. The SM465 can be found in Chevrolet and GMC full-size trucks, Blazers, Suburbans, among other models.
What’s the difference between M20 and M21 gearbox?
An M21 has a taller first and third gear than the M20. M21 was predominantly behind a 308 and M20 behindA 253.