Technical Four Speed Muncie Tech Info

Stumbled across some info that I thought would be helpful for those who enjoy having a 4 speed in their vehicle. Feel free to add any other info that might help others with these transmissions.

 

Rebuilding

 

Can't say I ever rebuilt an manual transmission that could be fixed with just bearings and synchro rings, they all needed gears, synchro hubs and sliders also. Maybe I was just to picky.

 

Thanks for posting this. I’ve got two on the shelf and one is pretty noisy. I’ll probably have to go through it if I decide to use it. More good info for the reference library.


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M-22s have a drain plug and are usually noisy.... I let one go for 4 bills some years back...

 

The straighter the gears...
(Say what sonny?)

 

A second drain plug can be added to earlier Muncies and was standard for 1970 and later transmissions so that isn't a sure way of checking for M22s. Since the most common ones are 1969 and later, just check the assembly code that looks something like this: P9A22 C. Look for the C at the end...it means M22. Also the letter after the P is the year..9 for 69..0 is 70..and so on.... there were M22s made before 1969..but they are super rare...the vast majority of M22s are going to be 1969 and later.. Either early or late..no rings on the input and look at the straighter cut gears. Count the teeth on the input shaft...all M22s are close ratio too.

They are noisy....like a kinda quiet gear drive instead of a timing chain.

 

The M-20 (wide ratio) for my 67 Nova is a "parts barrel" built trans, I had the guy that sponsored the turbo 400 in my race car build it in 1983.
It is basically a 69/up main case and internals with the earlier sìde cover assembly so the early style factory shifter could be used, also has the speedo outlet on the passenger side which is done so the shifter can mount farther forward for the earlier Novas.



66-67 Nova shifter.


This is also a good Muncie ID source.
http://chevellestuff.net/qd/muncie.htm

 

Roger that!
In 1970 I was 16 and had just got my drivers license and was given the (most memorable) opportunity to drive a new LS6 Chevelle with an M-22.
What a beautiful noise!

 

Almost sounds like a very loud dentist drill at high rpms....
The one I sold came out of a very rusty 1969 SS F-body.... I ended up sending that one to the scrapyard after I stripped it of all the goodies...

 

My Coupe has a M22, AND a Quick-change! It's LOUD!!!

 

The only thing missing then is the Pete Jackson gear drive I have, it's the "noisy" one.
Brand new, installed, never fired, you can have it.
One of those "what was I think'n".
Now, back to Muncie 4 speeds.

 

w/a 327" and 3:08 rear, a rebuilt M20 was a wide ratio godsend. Ran it 100k mi. in my '31 coupe. The spread between gears was close to ideal.

 

I just did a m 20 for my o/t gto (80000 mile car), the reverse gear, bearings and syncho rings is all I had to replace. But it was a good working trans when I parked the car, 44 years ago.

 

That's why I got rid of my elec fan! haha Hated the sound!!!

 

very good.....

 

@Austin kays

 

Like the nova shifter..

 

Well, my M22, Rock Crusher just broke on me Sunday. Now, i'm looking for a M21 or M20 to replace it. This all depends on how much it costs to repair it.

 

That's why Munchie prices are high these days, many of them went boom long ago

 

Broke a 68 muncie banging 2nd showing off, went bang...sounded like driveshaft was coming thru floor.

 

I just got one,thinking of putting it behind a 270 gmc 6 inline

 

Thanks for posting the info. I have three Muncies. Will probably have more sooner than later.

 

Beware of the NO GROOVES on the input. I ran into one with out grooves on the input and a large 1 inch cluster pin. Turned out to be an M20 that had the input replaced once in its life. They used the grooves to identify them at the factory but replacement ones have no need for them.

 

But at least they shift

But at least they shift
WAY better than a toploader...

 

I guess that says something about those Shiverlay engines in front of them!

 

I have a rebuild kit waiting for warm weather. 70 sbc chevelle wide ratio muncie gets freshened. I have a 65 wide ratio, came ftom a 34 street rod, quietest muncie I ever had, absolutely smooth.

 

Try a Hurst Comp Plus shifter w/it. Abs. Sweet! For a narrow body car (A), extend shifter up and a couple inches of jog right.

 

I had some custom shifter levers made, reg carbon steel. Machinest did a nice job.

 

Ah, the Chebbrainwashed- all it says is the aluminum-cased Munchies were weak- which they were- and a small percentage still are lol.. Many a Munchie has been grenaded by mild small-blocks- didn't take that much