How can you tell the difference????

 

Only way to be sure is to look at the gearset. This site compares the M22 gears to M20 gears (same as M21 except for ratio):

http://www.gearzone.net/muncie3.htm

 

I think on the imput shaft there is single ring around it for a M21,double for a M20 and no ring for a M22.

 

only real mjor differnce is the M-22 is heavyer built then the m-21

The M-22 in the Rock Crusher after all.

 

m22 is a straighter cut gear than the M20 and 21. straighter gear cuts can tolerate more power. jerico and other big name trasn builders often use straight cuts gears and m22 i think is cut at a 45. m20 and 21 are more, but i don't remember how much.

 

So the m-20 M-21 or the M-22 Rock Crusher???

 

The M22 is the "Rock Crusher" because of the whine of the straighter cut gears. It is stronger than the M20 wide ratio and M21, but it is not indestructable. I know! I have destroyed them all. The Super T10 is just as strong IMHO as the M22 even though I have broken that one too

 

Well Cool stuff the AMX has the Crusher....