Home of the world's best 4 speed muncie transmissions and parts. We also offer muncie rebuild kits, racing parts and m22 rock crusher transmissions.
Last time we talked about how to distinguish a Muncie four-speed transmission from a Saginaw or BorgWarner and the different types of Muncie transmissions, including the wide-ratio …
The first time I heard the term "rock crusher" was in reference to the transmission in the 1967 L88 Corvette. Due to the low gear angle there is a fair amount of gear noise, really like a medium / heavy duty truck transmission. True enough the M22 did trickle out the door in 1965-67 and was buried in the option lists.
Here is some test data from the 2.96 ratio Muncie transmissions that I used to build. All standard helix units failed at ~320 ft-lbf of torque with about 0.030" case stretch. All of the low helix sets failed at ~390 ft-lbf of torque with about 0.050" case stretch. All of these cases split at the small end of the counter shaft and shredded ...
Learn more about the different types of crushing and crushers used in the aggregates industry.
The most popular question has to be that everyone thinks they have the famous "rockcrusher" M22 4 speed. This had the same gear ratios as the M21 but with a heavy duty gearset. The reason you may ask? Well it …
The M22 transmission has a 20 degree helix angle on the gear set as opposed to a 45 degree angle found on the M20 and M21 and were made with a higher nickel alloy. The straighter angle was designed to produce …
What makes the Rock Crusher so popular in street rods and drag cars? The M22 uses high-nickel-content-alloy straight-cut gears that have less of an angle than the M20 and M21 gears.
A young guy would bring his car into his shop for a trans rebuild/fix and say the trans was an M-22 rock crusher. Well he would swap out the gears putting in a cheap set of M-21 gears (same ratio ) and then fixing the synchronizers that was the problem to begin with and KEEPING THE m-22'S.
The Muncie four-speed was produced in two ratios: the wide ratio (M20) and the close-ratio (M21). That being said, there was a second, close-ratio version (M22) that was developed to survive duty behind engines with a higher torque output, and was known as the "Rock Crusher."
STRONGEST Direct Replacement M22 With NEW Muncie AUTO GEAR Upgraded Ultra CASE With The Strongest M22w WIDE RATIO or Close Ratio Gears for a 4 SPEED TRANSMISSION. A GREAT HEAVY DUTY …
An M-22 holds up well. The downside is that it tends to make noise. It will rattle at low rpms and whine at higher rpms. The M22 is called the Rock Crusher. "Dump the Rock Crusher," hot rodders say. People think all Muncie …
The Gear Box is the source for Muncie Parts like the new assembled M22 SUPER ROCK CRUSHER 4 speed kit with micro super finish or downshift case support.
Identifying Muncie 4-Speeds. Several things are needed to identify a Muncie correctly. The first is a main case casting number. Second a count of the input shaft and output shaft splines and if any rings or grooves exist around the input shaft splines. Third are date codes and VIN numbers that help confirm that the above case and gears belong ...
Totally rebuilt M20 & M21 transmissions are going for $1500 to $1800 range. Honestly, I didn't see any M22's much higher than that (and rebuilt). I never had any interest in the M22 personally as my first Chevelle (L78) in '67 came with the M20 and I simply loved it hooked with 4.10 posi.
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. The …
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". The higher nickel alloy allowed for more impact of the gears.
Chevy Transmissions: Muncie M22 "Rock Crusher 4 Speeds were made From 1965 TO 1974: The most popular transmission of it's time for high performance cars built for Chevrolet and all performance oriented G.M cars. They have the same gear ratios as the legendary M21 but with a heavy duty gearset.
I want to eventually put an M22 in my Chevelle, but don't want to pay the outrageous prices for OEM units. I just want the same gear ratios, and that trademark rock crusher sound. Being stronger would just be an added benefit.
On this document the 4 speed transmission option code listed the transmission as an M20. In 1965, all 4 speeds were ordered initially by the M20 4 speed designation. Depending upon the rear axle ratio, Chevrolet supplied either the M20 wide ratio or M21 close ratio transmission at their discretion.
What makes the Rock Crusher so popular in street rods and drag cars? The M22 uses high-nickel-content-alloy straight-cut gears that have less of an angle than the M20 and …
There also was a second, heavy-duty close-ratio version: the "Rock Crusher" (M22) that was offered on some of the high-performance big-block models, starting with the 1965 Corvette.
New Super Heavy Duty Direct Replacement and Strongest M22's Made With Muncie Auto Gear Upgraded Ultra Case and Strongest M22 Close Ratio or Wide Ratio Gears. 10 OR 26 spline input and large 27 OR 32 spline output shaft. C355 Forged Aluminum Mid-Plate. Super Tail. AG Roller Side Cover. A great Super Heavy Duty Rock Crusher M22 for …
from Southern Ok. ""You can outfit an M20 or M21 with Rock Crusher type gears, OR actually make a 3 speed O/D out of a 4 speed case. Forth being the overdrive obviously.. Actually the 3rd gear station becomes the OD and the 4th gear station becomes 3rd,so the shift pattern is a little d,1-2-4-3.
I have heard that the m22 "rock crusher" is the best tranny for high horsepower applications. What about the m21? How reliable is a rebuilt m21 in mid to high horsepower applications?
The M22 transmission has a 20 degree helix angle on the gear set as opposed to a 45 degree angle found on the M20 and M21 and were made with a higher nickel alloy. 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.
NEW DESIGN MUNCIE M22 ROCK CRUSHER CLOSE RATIO 4 SPEED. THIS IS THE M-22 TRANSMISSION THAT GM COULD NOT BUILD! Newly designed STATE-OF-THE-ART Muncie front case from "Auto Gear". This is by far the "BEST" replacement aluminum case ever built for a Muncie! The front bearing is a "SEALED" bearing, and slightly thicker …
In 1965, GM introduced an even more robust version of the Muncie transmission, known as the M22 or "Rock Crusher." This transmission, with its distinctive whine, became synonymous with high-performance cars of the era. The M22 featured straighter cut gears, providing a more aggressive gear mesh for increased strength and durability.
This is the standard Muncie 4-speed case. It has a seven-digit serial number cast into the case on the passenger's side. These are usually the first numbers used to start the identification process. This is Brian …
M20 has weak internals and case but ok for street and chirping street tires, the M21 is a better choice for muscle on the street and a little weekend drag racing but the case is week Ive sheared the case ears off and twisted off tail shafts when running wrinkle wall slicks, the M22 (the rock crusher as we racers called them) are designed to ...
Muncie M22 REBUILD KITS: Quality parts from our inventory are assembled into kits for rebuilding M22 4 Speeds from 1965 to 1974. Kits are priced at $165.00 freight paid in US only. Rebuild Kit includes the following items: Gasket Set; Shift Shaft Seals; Rear Tail Housing Seal and Bushing for both the 27 and 32 Spline Main Shafts; Syncronizer ...
BTW, you can now buy high-quality M22 "rock crusher" style wide ratio gearsets! Tops on my Christmas wish list...
To understand the evolution of the Muncie 4-speed you have to look at a series of engineering platforms that led to the final design of this transmission. The Muncie design has roots going back to 1935. I took …
A tired rear bushing will give you a wobble under load ; the M22 "rock-crusher" noise is just in the cut of the gears, and quits once you shift into 4th . M21 Muncie's are fairly quiet till they come unglued .
