We are restoring a 72 Chevelle SS and would like to use a Muncie "Rock Crusher". Is there anyone out there that and tell me the difference between a Muncie M22W and a M22 Rock Crusher. I have tired to look online but not finding anything to help. I would appreciate it.

Thanks.

Someone correct me if I'm wrong but I think the M22 rock crusher is a close ratio trans with straight cut gears vs. normal helical cut gears?

In the beginning, the M-22 was the Heavy Duty Muncie, and it was available ONLY in the close ratio version (2.20:1 first gear ratio). The primary difference between the regular close ratio Muncie (M-21) and the HD Muncie was the angle at which the gear teeth were cut. The M-22 gear teeth are cut at a noticeably lower angle (not quite at a straight angle as some people say). This lower angle of the teeth imparts greater strength to the gears, but it also increases the noise caused by the meshing of the gears. This higher level of noise is where the nickname "Rock crusher" originated.

There are now aftermarket replacement gears, gear sets and complete reproduction Muncies available. The reproduction trannys are available in all of the original Muncie gear ratio versions, including the Heavy Duty M-22 version. Since the original M-22 was ONLY available in the close ratio version, there is NOW an M-22W. This M-22W version is simply a wide ratio version (thus the W) of the M-22.
Since the M-22 was only a close ratio tranny, it was usually only available, and more compatable, with the lower ratio rearend gears such as 3.70, 4.10, etc. Now, with the availability of the M-22W, it is more compatable with the higher rearend gear ratios such as 3.07, 3.31, 3.55, etc.
So, that's all the M-22W is, it's just a wide ratio version of the M-22-----------------------------AND LONG OVER DUE!!!! :thumbsup:

The M-22 was first available as an RPO (Regular Production Option) in 1966. Although, there seems to be sufficient documentation that a VERY small quantity (MAYBE 20-30) of M-22s were assembled into a few 1965 Corvettes with the 425hp/396 engine. It also APPEARS as though they were assembled in modified main cases. The last 3 numbers of the casting number on the main case were milled off and 3 new numbers were STAMPED in the place of the removed numbers. The cases were also bored out to accept the larger 1in cluster gear shaft which became standard with the 1966-later Muncies. IT IS EXTREMELY UNLIKELY THAT ANY OF US HERE WILL EVER RUN ACROSS A 65 M-22!

Great write-up Tom........

I just want to add that the M22W has a 1st gear ratio of 2.56:1.

As Tom stated, this is a great addition for the Muncie 4 speed AND my personal favorite gearset.

Not to cross forums, but just to clarify things, there is no such thing as an OEM M-22 "wide" ratio. The M-20 is a wide ratio, the M21 is close ratio, the M22 is close ratio HD. I think the tranny you're refferring to is from Auto Gear Equipment. They make upgraded Muncies that you can order with any of the standard ratios & some custom ratios, in standard gear helix or the "M22" style low angle helix.

Lookieheer: http://www.autogear.net/muncieproducts.htm

Tommy

There is also no such thing (officially) as an M22 "rock crusher"... the "rock crusher" name comes from the noise generated by the reduced helix angle on the gears...

Not entirely sure, but I think the new "M22 Wide" still uses the same helix angle, and therefore, probably just as noisy...

The differences...
the old "Rock Crusher" was a "close ratio trans, the same as the M21... the new "wide" in a widfe ratio, similar to the M20 (ratio-wise)...

Both version will have similar RPM drops between 1st-2nd and 2nd-3rd, but the wide ratio will have a bigger drop between 3rd-4th, hence the "wide ratio" name...

the "wide" also features lower overall ratios in 1st, 2nd and 3rd gears, helping to compensate for higher, "freeway friendly" gears, and still provide a nice launch, but allowing that "freeway freindly" gear to be utilized in 4th gear...

Great write-up Tom........

I just want to add that the M22W has a 1st gear ratio of 2.56:1.

As Tom stated, this is a great addition for the Muncie 4 speed AND my personal favorite gearset.

Do the wide ratio gear sets (M22W) have the same lower angle gear cuts as the original M22 and are they as strong?

Our Chevelle has the M21, with the same gear ratios as the M22, and 4.10 gears. While having the M21 rebuilt, I installed my spare M20. For all around driving I preferred the M20's lower first gear. Not a big difference but it is noticeable.

Do the wide ratio gear sets (M22W) have the same lower angle gear cuts as the original M22 and are they as strong?

So far they seem to be every bit as strong and the do have the same gear angle as the standard M22.

I have one in a 543 69 camaro, one of the first ones out there and it's still going strong.

There is also no such thing (officially) as an M22 "rock crusher"... the "rock crusher" name comes from the noise generated by the reduced helix angle on the gears...

Not entirely sure, but I think the new "M22 Wide" still uses the same helix angle, and therefore, probably just as noisy...

The differences...
the old "Rock Crusher" was a "close ratio trans, the same as the M21... the new "wide" in a widfe ratio, similar to the M20 (ratio-wise)...

Both version will have similar RPM drops between 1st-2nd and 2nd-3rd, but the wide ratio will have a bigger drop between 3rd-4th, hence the "wide ratio" name...


the "wide" also features lower overall ratios in 1st, 2nd and 3rd gears, helping to compensate for higher, "freeway friendly" gears, and still provide a nice launch, but allowing that "freeway freindly" gear to be utilized in 4th gear...

Dead-on. In drag racing, the M20 is sometimes preferrable with larger displacement engines because of the deeper first gear ratio. The extra torque compensates for the wider gap in ratios. The M21 was mostly used by GM on 3.70 & numerically higher ratio rear axles, the M20 on 3.55 & lower ratios. The M22 was set up for the original Z28s to help with the rigors of road racing in the Trans Am series, hence the lower helix gears, to allow faster shifts. Theoretically, straighter gears aren't really much stronger, but that's just a matter of opinion for some. I'm not going to start dissecting the engineering differences between straight cut & helical gears.

Tommy

So far they seem to be every bit as strong and the do have the same gear angle as the standard M22.

I have one in a 543 69 camaro, one of the first ones out there and it's still going strong.

I think a M22W gearset might be in my future! I had a SBC with an M20 with 4.56's and that was a nice combo out of the hole.

Now I have a 502 with 3.55's and feel the BBC will love the greater RPM drop. Combine that with the traditional gear whine it doesn't get any better!

There is also no such thing (officially) as an M22 "rock crusher"... the "rock crusher" name comes from the noise generated by the reduced helix angle on the gears...

Not entirely sure, but I think the new "M22 Wide" still uses the same helix angle, and therefore, probably just as noisy...

The differences...
the old "Rock Crusher" was a "close ratio trans, the same as the M21... the new "wide" in a widfe ratio, similar to the M20 (ratio-wise)...

Both version will have similar RPM drops between 1st-2nd and 2nd-3rd, but the wide ratio will have a bigger drop between 3rd-4th, hence the "wide ratio" name...

the "wide" also features lower overall ratios in 1st, 2nd and 3rd gears, helping to compensate for higher, "freeway friendly" gears, and still provide a nice launch, but allowing that "freeway freindly" gear to be utilized in 4th gear...

The M22W has the same RPM drop in all gears. It does NOT have the big RPM drop from 3rd to 4th like the M20.

The M22W has the same RPM drop in all gears. It does NOT have the big RPM drop from 3rd to 4th like the M20.

This is news to me and I own one. Course, its still in the crate but I thought it did have the wider 3 / 4 spread, hence the "W" which I thought pertianed to "wide" which I thought pertained to the 3/4 split. :confused:

The M22 was set up for the original Z28s to help with the rigors of road racing in the Trans Am series, hence the lower helix gears, to allow faster shifts.
I heard it was designed for Road Racing, but I always heard it was originally for Corvettes, with Z28/Trans Am was a natural extention... I don't think the helix design changes the shifting speed, that would be the synchros etc (not really "dogs", but whatever they are called; those little teeth)... The helical cut gears are in constant mesh...

Theoretically, straighter gears aren't really much stronger, but that's just a matter of opinion for some. I'm not going to start dissecting the engineering differences between straight cut & helical gears.

I have also heard that the design didn't really use the "straighter" gears for increased gear strength (nice side benefit), but mainly the reduced helix angle imparted less stress on the tramsmission case do to constant upshifting and downshifting under power... The lower helix caused the gears NOT to push as hard against the front and rear of the case...

The M22W has the same RPM drop in all gears. It does NOT have the big RPM drop from 3rd to 4th like the M20.

Well... Not according to the link on your website... Grantesd this is 'gear sets'...


http://www.autogear.net/pdfs/kitcontents.pdf (http://www.autogear.net/pdfs/kitcontents.pdf)

I do see where the ratios are different compared to the M20, I have been mislead... I was told (along time ago, much like Beaux) that the ratios in the M22W were the same (relatively) as the M20 (I think it was the earlier GM version, 2,56 first)...

But the ratio differences for the M22 are .746, .777, .785 (1-2, 2-3, 3-4)
forthe M22W, the ratio differences are 0.685, 0.780, 0.732, so they are not the same for each gear split... It appears as though the 1-2 shift now has the wider drop, while 3-4 is kles than the M20...

There were TWO different M-20s (and I'll address this more thoroughly at the very bottom).
There was the 63-65 version, and the 66-74 version.
The early version had a 2.56 1st gear and the later version had a 2.52 1st gear. THUS, the split between gears of the early and late versions was different.
The "new" M-22W has the early style 2.56 1st gear, therefore, it does NOT have the same gear split of the later, more common M-20s.
This makes the new M-22W slightly more compatable with rear gear ratios in the 2.73-3.55 range.
Soooooooooooooooooo, if your car has a more hiway friendly gear (or you would like for it to have), then the M-22W would certainly be a better choice.

Do I have an M-22W in the 70?
No, but I sure would like to have one.
But, since I build my own Muncies, and, don't have $1800+ readily available to drop on one, I'll stay with my stock M-20s as long as my spares and spare parts last. :thumbsup:

Per the above comment about the M-20.
In the beginning, there really was NOT a seperate M-20 or M-21 (or even an M-22).
In the 63-65 cars, the RPO (Regular Production Option) for a 4sp tranny was M-20. There was NOT such a thing as the M-21. Depending on rearend gear ratio of the vehicle receiving a 4sp tranny (M-20), GM made the decision (NOT the buyer) as to which ratio tranny was installed in the vehicle. It was either a close ratio (later to become RPO M-21), or wide ratio which was the later M-20. In 1966, this changed to RPO M-20, RPO M-21, RPO M-22, and the customer more or less selected the 4sp option (within limits, for example, you couldn't get the M-21 with a 3.07 rear).
The M-22 (HD, Rockcrusher, whatever you choose to call it) WAS NOT available as an option until 1966. YES, YES, YES, there seems to be reasonable documentation that a few (20-30) HD Muncies were installed some 1965 Corvettes with the 425hp/396. So far, that documentation seems to be VERY legitimate.
As for us old timers, I still refer to all Muncies as a "Wide" or a "Close" ratio Muncie. I came from this era of perf cars and 4sp trannys, and that is the way they were referred to (since back then there was no such thing as an M-21). I only use the terms M-20, M-21, M-22 here because you young whipper snappers force me to! :D

The M22W and the M21W has a different tooth count in 2nd and 3rd gear, that is why it is geared different from an early or later M20 from 3rd to 4th. Actually, 1st to 2nd gearing is a bit wider than an M20.

Bottom line, if you install an M22W or an M21W and never tell anyone it is the "W" gearset, they'll never know. I have tested many customers and they swear their transmission was a close ratio gearset because of the even RPM drop though all gears.

To compare things a bit more between the M22 and the M22W:

If you had a combination of an M22W with a 3.31:1 differential, that would be the same as using a regular M22 with a 3.85:1 differential in your first gear take off.

Here is the formula for comparing:
new trans 1st gear x rear differential / original trans 1st gear
M22W x differential gear / M22

2.56 x 3.31 / 2.20 = 3.85
M22W & 3.31 = M22 & 3.85 on your 1st gear take off

2.56 x 3.55 / 2.20 = 4.13
M22W & 3.55 = M22 & 4.13 on your 1st gear take off

2.56 x 3.73 / 2.20 = 4.34
M22W & 3.73 = M22 & 4.34 on your 1st gear take off

These new "W" gearsets are tops.

The M22W and the M21W has a different tooth count in 2nd and 3rd gear, that is why it is geared different from an early or later M20 from 3rd to 4th. Actually, 1st to 2nd gearing is a bit wider than an M20.

Bottom line, if you install an M22W or an M21W and never tell anyone it is the "W" gearset, they'll never know. I have tested many customers and they swear their transmission was a close ratio gearset because of the even RPM drop though all gears.

To compare things a bit more between the M22 and the M22W:

If you had a combination of an M22W with a 3.31:1 differential, that would be the same as using a regular M22 with a 3.85:1 differential in your first gear take off.

Here is the formula for comparing:
new trans 1st gear x rear differential / original trans 1st gear
M22W x differential gear / M22

2.56 x 3.31 / 2.20 = 3.85
M22W & 3.31 = M22 & 3.85 on your 1st gear take off

2.56 x 3.55 / 2.20 = 4.13
M22W & 3.55 = M22 & 4.13 on your 1st gear take off

2.56 x 3.73 / 2.20 = 4.34
M22W & 3.73 = M22 & 4.34 on your 1st gear take off

These new "W" gearsets are tops.

I've already put this on my Christmas list and sent it to Santa............ I should get the letter real soon:D

Tom, Jody - kind of a given but im saying it anyway - you guys rock!


Just saying thanks for the time you spend here. big ol "Hell yeah!" to both of ya

:thumbsup::beers:

Jody and anybody else into this,

Can I buy a heavy-duty Italian gear set in the M20 wide gear ratio w/ the 4th gear OD that I can install in my stock, '67 Camaro's M20 case, iron/steel midplate and all??

And will it hold behind a 496 BB producing 600 T?

Please PM me prices if this is sold?

pdq67

I love hearing this info from Tom and Jody. Real good info.
I have the Autogear M22W in my 71 with 3.55 rear since early this year. I have no complaint. Works excellent with the 3.55 gear, and the whine it makes in 1 st, 2 nd and 3 rd causes the goosebumps to bleed, its awesome !!!!!
After removing the boring T400 for the M22W, my driving fun is at its max. :thumbsup:

I love hearing this info from Tom and Jody. Real good info.
I have the Autogear M22W in my 71 with 3.55 rear since early this year. I have no complaint. Works excellent with the 3.55 gear, and the whine it makes in 1 st, 2 nd and 3 rd causes the goosebumps to bleed, its awesome !!!!!
After removing the boring T400 for the M22W, my driving fun is at its max. :thumbsup:

Good to hear. Pretty much going the same route as you did with engine / trans but planning to run 3.42's on the rear.

I was going to do the whole 5 / 6 spd swap but now planning to stay with the 4 speed indefinitely. Its just "right" and this is all great news hearing that you guys are happy with yours or like / approve of the trans even if you dont run one.

Jody and anybody else into this,

Can I buy a heavy-duty Italian gear set in the M20 wide gear ratio w/ the 4th gear OD that I can install in my stock, '67 Camaro's M20 case, iron/steel midplate and all??

And will it hold behind a 496 BB producing 600 T?

Please PM me prices if this is sold?

pdq67

At this time only the 2.20 1st gear and the 0.086 4th gear ratio are available for the OD gearset.

FYI: if anyone has an M21 Muncie, the conversion for the OD gearset is only a three gear changeout.

Good to hear. Pretty much going the same route as you did with engine / trans but planning to run 3.42's on the rear.

I was going to do the whole 5 / 6 spd swap but now planning to stay with the 4 speed indefinitely. Its just "right" and this is all great news hearing that you guys are happy with yours or like / approve of the trans even if you dont run one.

I too was going to go with the 5 sp set up. Just didn't want to cut the car open at this time and not interested in the old X doug nash now richmond 5 sp. To each there own.

I too was going to go with the 5 sp set up. Just didn't want to cut the car open at this time and not interested in the old X doug nash now richmond 5 sp. To each there own.

Im with ya 110% :thumbsup::beers:

My happy day early this year:




http://img397.imageshack.us/img397/1986/backtogether234rp5.jpg (http://imageshack.us)

Installed my new m22w earlier this year. Went from a th350 and luvin it. Now I am a gear jammin fool instead of just a fool :D

Ah, that's a sweet looking tranny!

Notice the rear housing?

I want the new so-called Muncie 5-speed to have the OD gear in it, not like an internal shift tranny like they have made if not mistaken. Imho, an internal shift tranny AIN'T a Muncie by no stretch, call it something else, BUT NOT A MUNCIE!

I know, I know, I get carried away here!

pdq67

Ah, that's a sweet looking tranny!

Notice the rear housing?

I want the new so-called Muncie 5-speed to have the OD gear in it, not like an internal shift tranny like they have made if not mistaken. Imho, an internal shift tranny AIN'T a Muncie by no stretch, call it something else, BUT NOT A MUNCIE!

I know, I know, I get carried away here!

pdq67

When that Autogear 5 speed is proven, and the bugs are all fixed, I'll be looking into it.

Ah, that's a sweet looking tranny!

Notice the rear housing?

I want the new so-called Muncie 5-speed to have the OD gear in it, not like an internal shift tranny like they have made if not mistaken. Imho, an internal shift tranny AIN'T a Muncie by no stretch, call it something else, BUT NOT A MUNCIE!

I know, I know, I get carried away here!

pdq67

Well then you don't want one:thumbsup::thumbsup:

The new case, no longer a split case, has interal shift rail shifting.

There is a new gear set for the muncie, 2.95 low gear, made for the guys who want to use a 3.08. It uses a different main shaft to allow for the 22 tooth input. There also is a new reverse system coming out.

I'm thinking the 2.95 in my car with the 3.55 out back, damn:yes::yes::yes:

Well then you don't want one:thumbsup::thumbsup:

The new case, no longer a split case, has interal shift rail shifting.

There is a new gear set for the muncie, 2.95 low gear, made for the guys who want to use a 3.08. It uses a different main shaft to allow for the 22 tooth input. There also is a new reverse system coming out.

I'm thinking the 2.95 in my car with the 3.55 out back, damn:yes::yes::yes:


I'm with pdq67 on this one, if it is internal shift linkage and not produced by muncie, what makes it a muncie? Does it even have a side inspection cover or is it going to have a top plate?

I'm with pdq67 on this one, if it is internal shift linkage and not produced by muncie, what makes it a muncie? Does it even have a side inspection cover or is it going to have a top plate?

Last time I looked it wasn't a muncie. It's a new trans and I think it's called a Syracuse 5 speed.

You want a OD "Muncie" buy a muncie and fit a gear vendors OD unit on the back.

You want a 5 speed from Auto Gear it will not have a side cover and it will have shift rails.

Wally,

I'm NOT ragging on Autogear here at all, but they got off on the wrong foot quite a while back by calling their 5-speed a MUNCIE when it AIN'T!

And I wish them well w/ it as long as it doesn't end up costing a pound of flesh.

Heck, I'm fully able to design and build what I want except for one thing MONEY b/c I'm a graduate ME!! Gearhead to boot!

There are two type drive train units that flat trip my trigger and they are the old T-85 3-speed stick OD unit. I think that I would use an early '50's Packard tranny b/c it had a fully sync'd 3-speed stick in front of the OD unit for starters!

And the '69 Mercury Cougar Eliminator mechanical shift 2-speed rearend PROTOTYPE that I would dearly LOVE to be able to buy the rights to and then manufacture!!

pdq67

Well then you don't want one:thumbsup::thumbsup:

The new case, no longer a split case, has interal shift rail shifting.

There is a new gear set for the muncie, 2.95 low gear, made for the guys who want to use a 3.08. It uses a different main shaft to allow for the 22 tooth input. There also is a new reverse system coming out.

I'm thinking the 2.95 in my car with the 3.55 out back, damn:yes::yes::yes:

When is this 2.95 set going to be available? Will these be M22-style gears? What are the 2nd and 3rd ratios?

Why is the mainshaft different??? :confused:

Thanks!
John

Just a note:

The M22W set manufactured by Autogear was designed to be a better alternative to the M22 since most do not like the 2.20 1st gear ratio of the M22. It also has a better ratio spread then a conventional M20. It maintains the M22 gear helix angles.

BE CAREFUL!
There are people selling M22W sets made in Taiwan that duplicate the exact ratios of the M20. This is counter productive. I have not seen any failures with the Autogear gear set and we do sell alot of them.

NEW UPDATES FROM AUTOGEAR!
As mentioned by Wally there will be new mainshafts and reverse gear designs as well as new mid plates. Your old parts are fine. The updates are a decision to assure the consumer is getting an Autogear transmission and not just an Autogear case with new Taiwainese gears which seems to be a growing trend on Ebay.

Wally,

I'm NOT ragging on Autogear here at all, but they got off on the wrong foot quite a while back by calling their 5-speed a MUNCIE when it AIN'T!

And I wish them well w/ it as long as it doesn't end up costing a pound of flesh.

Heck, I'm fully able to design and build what I want except for one thing MONEY b/c I'm a graduate ME!! Gearhead to boot!

There are two type drive train units that flat trip my trigger and they are the old T-85 3-speed stick OD unit. I think that I would use an early '50's Packard tranny b/c it had a fully sync'd 3-speed stick in front of the OD unit for starters!

And the '69 Mercury Cougar Eliminator mechanical shift 2-speed rearend PROTOTYPE that I would dearly LOVE to be able to buy the rights to and then manufacture!!

pdq67

Oh my God, a ME and a gear head, we a in deep trouble boys:)

My son-in-law is a engineer, he and I both went to the Univ of Maryland, go Terps:hurray:

I don't know if all engineers solve problems the way he does, drives me nuts trying to help him hang drywall:sad:

Well, the trans is nearly done as are the new reverse gears, mid plates and main shaft. I live close enough that I plan a trip to see the new unit when finished.

I'm working full out on the 67 and expect to have it running and at the 09 gathering, if I get lucky with the new 5 speed:yes::yes:, if not with the M22W that's in there now.

Warm up all those 600 HP rat motors out there, one very nasty mouse motor will be on the hunt;);)

I heard it was designed for Road Racing, but I always heard it was originally for Corvettes, with Z28/Trans Am was a natural extention... I don't think the helix design changes the shifting speed, that would be the synchros etc (not really "dogs", but whatever they are called; those little teeth)... The helical cut gears are in constant mesh...






I have also heard that the design didn't really use the "straighter" gears for increased gear strength (nice side benefit), but mainly the reduced helix angle imparted less stress on the tramsmission case do to constant upshifting and downshifting under power... The lower helix caused the gears NOT to push as hard against the front and rear of the case...

Yeah, I wasn't too clear on the shift speed thing. I'm still not too sure how to verbalize what I'm trying to say. :clonk:

As for the gear strength/helix thing, you're right. That's what many people confuse about the difference in strength between straight & helical gears. The tranny ends up being overall more reliable, it isn't just about gear strength alone. The more helix you have on two gears, the stronger the contact area due to increased load spread. In other words, the individual teeth are stronger on a straight cut gear because they are larger, but the surface area that the load is spread out on is smaller, so depending on tooth size & helix, there may be no appreciable advantage of one or the other. Like I said, gear strength is somewhat of a subjective issue. Many people see it many different ways.

Tommy

Like I said, gear strength is somewhat of a subjective issue. Many people see it many different ways.

Amen to that:thumbsup::thumbsup:

I seems that Tremac is just as guilty of subjective gear strength as the next vendor but the main difference is they are not willing to tell anyone how they arrive at the numbers they use.

Just a pet bitch with me;););)