My 1971 LT-1 is presently in the shop having assorted repairs. I bought it only recently. It is not the ZR-1 option, however, I know that the car has heavy duty suspension and brakes. It will be some time before the mechanic can get it back on the lift. Is there a possiblity that the car could be equiped with the
M-22 transmission?

d.s.

I have never done this but I would suspect there are casting numbers on the case you could try to match up with what an M22 should be. you could also just ask the shop to pull the side plate and look at the gears. The M22 teeth are square and the M20 and M21 are angled. At least that is the way they are described in books. The M22 is also supposed to be much noiser than the other two because of the tooth configuration.

If it is an m-22 it will have a loud whine when driving, especially on acceleration. The m-20 and m-21 should not make any noise if they are tight. My wife's 68 camaro has an m-22 in it and it is definatley louder than the m-21 in my 73 vette. Here is a link that may help with positive identification.

http://www.yearone.com/updatedsinglepages/Id_info/muncie.htm

Great link Woody...!!! Thanks!


Jim O.
Save the Wave...!!!

Hi
Don't think you can see the difference on the casting numbers of the trans.
The input spline number tells you what it is or like already mentioned, the gear form.
What's the big deal with this M22 except for the ridiculous price ? They aren't any stronger than M20 or M21, are they ?
As far as I heard, they just produce less friction between the gears, hence the use in racing cars.
If you got one in your car, sell it and get a nice 5 or 6 speed overdrive instead.
Good luck Gunther

The M-22 is much stronger than an m-20 or 21. The straighter cut of the gears puts a lot less end to end stress on the case. The thicker teeth are much stronger than the helical cut gears in the other two muncies. There are several ways to tell if it is one of the three. But the only 100% sure way is to open it up and look at the gears. Although not cut square, the M-22 teeth are at about a 20 degree angle as opposed to the nearly 45 degree cut of the M-20 and 21. Also the teeth are thicker than the others. I would not trade or sell my M-22 at any price.
The m-22 can take a hell of a lot more torque than a 5 or 6 speed, unless you go to a Jerico or some other aftermarket tranny. If you give me all the numbers, cast and stamped on the tranny, and the spline count, front and rear, I can probably tell with about 90% accuracy which one it is. Also, if there are any rings cut around the input splines, that will help in identifying it.