M-22 "Rock Crusher" Identification. The M-22 close-ratio transmission is easily identified internally from the M-20 and M-21 versions by the angle of the gear teeth. The M-22 was only produced in a close-ratio version, so it will not appear on models with high rear-axle ratios (3.55 or lower numerically) unless someone has changed it.
The M22 was eventually dubbed the "Rock Crusher". It is a common misconception that all Muncie transmissions are "Rock Crushers", but it is only the M22 that deserves that name. The M20 and M21 were both release in …
In addition, many GM high-performance engines came with M-22 "Rock-Crusher" in the 1970-73 years, however an early version of the M-22 was available as early as 1965 in …
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.
Across the top of the page are the words "First Build 4/15/65 – 1st Shipment 4/19/65, recap of M22 (Rock Crusher) Trans." By comparing these M22 transmission …
The M22 was eventually dubbed the "Rock Crusher". It is a common misconception that all Muncie transmissions are "Rock Crushers", but it is only the M22 that deserves that name. The M20 and M21 were both release in 1963, but it wasn't until 1965 that the M22 hit the market.
In the early 1960s, GM was looking to move away from the four-speed manual transmissions it had been purchasing from BorgWarner and bring production in-house. The twist was the four-speed gearbox found in the first two generations of the Chevrolet Corvette—the BorgWarner T10—had in fact been built using plans …
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 …
M-22 "Rock Crusher" Identification. The M-22 close-ratio transmission is easily identified internally from the M-20 and M-21 versions by the angle of the gear teeth. The M-22 was only produced in a close-ratio version, so it will not …
Many people know about Muncie transmissions and the famous M22 "rock crusher" transmission that has straighter cut gears that allows you to bang the gears without pushing in the clutch.
The straighter angle was designed to produce less end loading of the gear train and less heat but created more noise, thus the nickname "Rock Crusher" was born. Another misconception is if you have a drain plug you have a M22.
In addition, many GM high-performance engines came with M-22 "Rock-Crusher" in the 1970-73 years, however an early version of the M-22 was available as early as 1965 in Corvettes. Proper identification of the transmission type is absolutely necessary, but sometimes difficult due to several factors.
Across the top of the page are the words "First Build 4/15/65 – 1st Shipment 4/19/65, recap of M22 (Rock Crusher) Trans." By comparing these M22 transmission assemblies to Chevrolet's 1965 transmission identification codes, I found a perfect match.
The M22 'Rock Crusher' featured a one-inch countershaft pin bore and shot-peened gears with aggressive helix angles that reduced heat and stress but also increased noise, leading to the nickname as the transmissions rattled their way down the road.
The M22 Rock Crusher would come later to accommodate the heavy twist of Chevrolet's big-blocks in the mid-1960s. The M20 and M21 transmissions produced from 1963-'74 are easy to identify in both wide- and close-ratio units.
How to Identify Muncie 4 Speed Transmissions Identifying Muncie 4 Speeds III by Paul Cangialosi The most popular question has to be that everyone thinks they have the famous "rockcrusher" M22 4 speed.
