Rock crusher gear ratios

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. Muncie also had a second close-ratio transmission coded M22 and known as the rock crusher, which was used behind performance big-block engines and in some Corvettes

The 2.20:1 ratio is commonly designated as the Muncie M21 transmission. 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

Sep 15, 2010 Another change for the M22 was the new low helical-angle cut gear set which increased the inner strength of the transmission dramatically. This gearset was quite noisy and from all indications was called the “Rockcrusher” transmission from the

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. Step 1 Check the casting number, the production year and the gear ratios on the aluminum serial number plate attached to the transmission box

This a BRAND NEW SUPERCASE M22 4-Speed Muncie Rockcrusher Style Transmission. Each new Auto Gear transmission is built from genuine Auto Gear parts, the highest quality available. This is a BEEFY version of the original Rock Crusher transmission

Oct 30, 2008 This higher level of noise is where the nickname Rock crusher originated. There are now aftermarket replacement gears, gear sets and complete reproduction Muncies available. The reproduction trannys are available in all of the original Muncie gear ratio versions, including the Heavy Duty M-22 version

For instance an M20 is also an Opel 4-speed, an M21 is a Saginaw, the M22 is another Saginaw & M22 is also what GM in the US call their Hi-Torque Muncie “Rock-Crusher” box. The box in the XU-1 is called an M20 even though its ratios are closer to what we normally call an M21

4 Gear Trans Co Muncie M22 Rock Crusher 4 SPEEDS FROM 1965 TO 1974: This page is devoted to OEM Complete units; New aftermarket units and OEM parts and NOS parts. We have rebuild kits in stock and ready for shipment

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 than the original Muncie's

The M22 Rock Crusher would come later to accommodate the heavy twist of Chevrolet's big-blocks in the mid-1960s. ... Gear ratio set (i.e., A=M20) (This code was added to identify ratios. Some