VI Cutty

There's an M22 Rockcrusher for sale around the corner from me, and I'm debating whether it's worth buying for future installation in my '71 Cutlass.

The transmission is supposedly a fresh rebuild (I have to find out who built it) and came out of a '67 Camaro. Asking price is $1250 CDN "firm". I don't have any other information on it at this point. My assumption is that if a bellhousing is included, it's likely GM and not BOP pattern.

My car is currently a stock '71 Cutlass S, 350 SBO with TH350 column shift and bench seat. I keep toying with the idea of converting it to buckets/4-speed but don't have any conversion parts as yet, and haven't committed to the plan either...although I do know where an affordable pair of correct buckets are stashed away too...

I have a couple 455's, one of which I intend to drop in and a limited slip rear end with unknown ratio (haven't jacked it up and counted rotations yet) also destined for the '71. I don't plan on going HP crazy with the 455 build and won't be drag racing the car.

Notwithstanding the rest of the parts I'll need to find for the eventual conversion, would this M22 be a good choice? What would be needed for the trans to fit and work in an Olds? I saw something about an Oldsmobile end housing?

What information should I determine or watch for if I were to check this transmission out?

I'm not in any rush to make those changes to the car as there are higher priority tasks to do first (can you say Engine Bay MAWs?), but will I be kicking myself in a couple years if I pass up this trans?

Octania

Close ratio transes were usually paired with a performance ratio final drive.

The M21/M22 trans ratios are "closer" to one another by means of the first gear being less deep- aka taller, numerically lower. Therefore not as much torque multiplication with the C.R. first gear as say the M20 in first. Why this pairing of C.R trans and P.R. final drive? because the final drive makes up for that with its extra helping of Torque Amplification. Because it is a Performance Ratio.

Consequently you may find that if you put a CR trans with a not so deep first gear in front of an economy ratio final drive with a not so deep multiplication factor, you end up with a real tough start.

Like starting out in 2nd or 3rd gear... all the time. With no way around it.

You should get counting turns and find out what you have there.

RandyS

IMO, a freshly rebuilt M22 is well worth $1250.00. That being said, a fresh M21 will hold up well with a mild build, and be a lot quieter.

1968_Post

Randy is correct about the noise factor... definitely something to consider. A well built M21 would work just fine behind most street applications.

allyolds68

A rebuilt M22 goes for over $2k so I'd find out why it's so cheap.


And as everyone said, there's no real need for it, an M21 will work just fine. You'll also need at least a 3.42 rear. You probably have something higher (numerically lower) in your 350 powered CS

VI Cutty

Hence why I'm not rushing into it. What sort of warning signs should I be looking for? My first concern would be if it's not a professional rebuild from a respectable shop.

At the moment, I have neither! How much more noise do the straighter cut gears make? I have to admit I enjoy the relative quiet in the car compared to my VW. It's nice to actually have a conversation without shouting!

The rear end in the car now is an open diff, no posi. I'm pretty sure the one I have in my '70 S parts car isn't original to the car but I won't make any guesses until I jack it up and check.

Thanks for all the input so far; it's a pricey conversion to consider without being properly informed.

4speed455

I believe the factory recommended 3.73+ gears with an m21/m22. I would say looks for an m20 wide ratio. I'm sure you already know that whatever crank you use will probably have to be machined for the 4 speed bearing unless it came from a factory 4 speed car.

steverw

I just bought and installed an M22 from Joe(JoesW31) here on CO. Its in my 65 Corvette, I sheared off the teeth shifting into 2nd recently on my M21. Yes the M22 whines, but its a cool whine, but only in 1 2 and 3rd gear. Its the strongest Muncie GM made. I love it. Joe has another M22 for sale. He is a great guy, he rebuilds these transmissions, and i guarantee its better than what came out of the factory. He is very meticulous. If your going to put it behind a 455 why not get the strongest. M21's are good no doubt, but if that trans is really a rebuilt M22, thats a great price. Problem is you dont know what was done to it, a mix of old and new? There are excellent gear sets to be had and there are cheaper Asian made ones. The good ones are made in Italy and 30% stronger than GM gears. The Asian made ones, who knows. I say check it out and if it checks out good then buy it, if thats your future plan. If your plan changes you can always sell it.

oldsmobiledave

Chevy used the M-22 with 3.31 gears in many 454 powered cars.

Olds used the M-22 with 3.42 and 3.73 gears (1971) behind the 455.

You wil be fine with 3.42 gears and a 26-27" tall tire behind a stout 350 or stock 455. A stock 350 needs a 3.73 gear. Of course you will be looking at 12-13 mpg tops with 3.73 gears.

VI Cutty

Got some photos of it and it looks more likely to be a 1966-70 M20 2.52 ratio 10-spline 1-in. shaft - 2 grooves - 27-spline output shaft.

Housing casting is 3885010 which places it from '65 to 67 and the output shaft has two grooves in it. Identified using http://www.hemmings.com/mus/stories/...feature18.html.

Hopefully the weather doesn't suck tomorrow so I can check my rear end ratio.

Would this be a better general duty choice for trans, then?

(And yep, I do know about having to drill an AT crank)+

Edit: Just talked to the seller, he doesn't have any specs on the rebuild but it was done by what appears to be a reputable shop in Washington state through the local GM dealer. I'm not sure whether the price is still a decent bargain now given that it's not an M22.

RetroRanger

I'm considering an MT swap at some point in the future.

After looking around at 5 speed kit prices (my first choice) I'm thinking a used 4 speed may be better for me. So after seeing a bunch of cl ads ranging from parts to completely rebuilt trans for 2kish the auto gear 4speed seems like a good alternative. New 4 speed trans for as low as 1600 if you did assembly or 1800 assembled.

I'm still researching but their page has a lot of info on it and they make some good arguments for a new trans VS rebuild an original

http://www.autogear.net/motorsports/

allyolds68

That price is no deal for an M20. Professionally rebuilt, guaranteed units sell for $1000-$1200. You can buy a decent, working, used M20 for $300- $600. A complete rebuilt kit with bearing, seals, syncro's etc runs less than $200.


Older (pre 68?) M20/21's used a 7/8" countershaft which was changed to a 1" in 68. Many of them (even 1") tend to leak at the countershaft hole

rootney

New aftermarket M22 clone from 5speeds.com
In the $2000-$2200 range.
Pretty bulletproof.
Has a 1st gear whine like the original.
Different ratios available.
I bought one for my 4 speed conversion project. '72 Cutlass , 455, 3.42:1 rear, centerforce clutch. I really like it.

Talk to Paul Cangliosi owner at 5speed.com.
Really knows his stuff. Check out the website.

George

My442

Had a M22 in the 442 I sold a few months back.


NOTHING screams muscle car like the gear whine of a M22.


Best upgrade I did to the car.


BTW - I ran it with 3.91 gears

bccan

Don't judge the trans model by the input shaft as there are many variations. The only proof of M22 status I would trust is pull the side cover & check the gear tooth angle/pitch.


In my experience the weak point wasn't so much the gears as the case breaking where the countershaft is supported. I was involved in a few loooong pushes home of cars with broken Muncies in my formative years! We may have lacked judgement & fear but thankfully had enough guys in the car to push while rotating in a driver as people's legs failed.

rootney

Click on this and have a quick look.
http://www.5speeds.com/newm22.html
these look like a Muncie but are designed incredibly tough.
Note the steel cross plate between the tail housing and main gearbox.
I love mine. I ordered the lower ratio first gear. Makes my 3.42 rear just like a 4.11 off the line.
The gear whine really sounds awesome.

George

VI Cutty

It's hard to compare prices with stuff in the US. A $2000 item there will cost me almost $2700 after exchange, and I still need to get it shipped across the border with brokerage fees and taxes. A rule of thumb that seems to be reasonably accurate is to double the USD price to figure what it would cost to get to my doorstep. That tends to open the price point considerably!

In the case of this one, although unused, it was rebuilt in 2007 and sat in a box ever since so unlikely that the builder will have any of the build information or warranty it now.

At any rate, while probably still a decent enough price it's not what I would consider enough of a bargain that I can't pass it by. I'll let this one go and hopefully find a better deal/more complete setup down the road.

stan 65 cutlass

does sound steep Clay if it is an m20 only. nothing wrong with an m20, thats whats in my car.

crash

F.Y.I.
1965 and older Muncies used 7/8" clusters...
1966 and newer Muncies used 1" clusters...

Hope this helps... Crash

oldsmobiledave

If you buy an M-20 stick with the 1971-73 version. Same goes with the M-21. Both received upgrades from the earlier versions.