This guy in a local car club is going to try to swap his t56 for the famed m22 "rockcrusher" 4 speed, can that be done? Woldn't the imput shaft be different?

 

I remember seeing an 01' SS driver who had converted to a 4-speed. I guess it can be done if you have the money.

 

I can't imagine for the life of me why anyone would ever do this. The T56 is stronger and the parts are far cheaper than a Muncie M22. Besides that, the M22 is just about the noisiest car transmission on earth. The ratios in the 4 speed are probably better for pure drag racing but you know longer have any overdrive and you give up about 100 lb-ft in torque capacity in trade for a huge whirring noise.

To each his own, but IMHO a worthless mod unless you simply must have that oddball package.

 

Why would he want to do that?

The t56 is a very strong trans, I don't know the exact strength ratings of the m22 but I can't imagine it is much better than the t56. With similar or better strength plus two overdrive gears, I don't see why someone would even want to try this? I would doubt the m22 input shaft is the same but not sure. I'm pretty sure there are more issues than just that though such as the clutch release mechanisms, hydraulic vs mechanical.

 

He is makeing the car a pure drag car. It is currently an auto and he is in love with the old 4 speed manuals. I like them too, but it is a lot of work when you could prablly do a t56 easier. He is having a shop build a m22 with a stroger case and internals to handle the engine he is building for the car (409 LT1).

 

what a waste of dough, time and effort

 

Too each his own I guess, Don't support the idea, but I didn't think it could be done.

 

props to him if he can make it happen, but I can think of a million other ways to spend the money.....

 

The T56 is the M22 of its day. better off looking at the Richmond transmissions where the ratios can be configured.

 

My grandpa has a couple of the famed muncie rockcrushers, i do beileve they are stronger then a t56 to a point, but swapping from a t-56 to one is crazy, and like someone mentioned hence the name " rockcrusher" they are extremly loud transmissions due to the fact of the strait cut gears instead of the heli-cut or whatever you want to call them, if i remember right that is.

 

Doesnt sound all that impossible ? Quite sure Lakewood has a bellhousing that it'll bolt to with a hydraulic slave mount, put in an 86-92 V8 flywheel, their bellhousing, and might have a little fun making the shifter hit the right spot.

Less weight, can handle a good amount of power, seems like he isnt hurting anything. Probably less than a good T56 clutch and rebuild.

 

I think that's close to right! The Munice M22 "rock crusher" used a 22.5 or 20 degree gear, if memory serves. The gears were "high nickel" gears. New (and improved) M22's are now being built. You can read about them at http://www.5speeds.com/muncie.htm

Rich Krause

 

I do remember reading that the straighter cut gears are the stronger they are. Wouldn't that make a m22 stronger than a t56?

 

All else being equal, I think that gears cut "straighter" are stronger. But there are so many other variables that it can't be automatically assumed that a given gear box is stronger just because the gears are cut with less of an angle. Another thing: the M22 had very close gear ratios and a high first gear (2.20), so a very high rear end (4.10's or higher) was needed to use one effectively.

Rich Krause

 

absolutely. I also came accorss that same website awhile back while i was toying with my shift points and found the ratio page quite informative since i didn't experience the muncies the first time around.

-brent