Is there any other ways to identify a muncie other than checking the part numbers and gear teeth and external differences..what I am concerned about is the internals. Is there any way to tell if the gear set or cluster is a genuine GM piece like some sort of GM markings that you can see through the side cover opening? They make cheap china ge****ts and other stuff these days and buying a used M22 is sort of a pig in the poke unless you know who owned and used it before or if anyone ever had it apart to replace something, thanks..
The simple way is to build your own using the "Italian Ge****ts" from Autogear in NY. The Italian gears are made by Antonio Masiero ltd, who are a proprietory manufacturer for a lot of euro auto and truck makers. They are tougher than GM and very high quality I've had 650 ft/lbs of torque through these gears [ the weakest link is the alloy casing ]
Look at the lower right side of the main trans case .... It should have a drain plug.... Like mine did.
The answer is no, not without pulling it apart, for everything that someone says will identify a m-22 there are 2 exceptions
As I remember, the Rock Crusher had straight cut gears and the other had helical cut gears. All had Aluminum case with the reverse lever on the tailshaft.
M22 had a co****r tooth pattern and less of a helical cut. Drain plug and fine spline don't mean anything. The Italians have some of the most modern gear cutting technology in use today. Ago
Not always true at least not in my case. My M-22 is 10 spline input with no drain and I've read that not all of them did have it
All 3925661 cases had drain plugs, not all of them are m-22s, the more you research the more you'll find the only way to be 100% is to open them up. But the real question is can you look inside and tell if you have cheap gears, I don't know of anyway to tell that without pulling apart.
i can tell you from experience that gm produced a m 21 ****** with a fine splined input shaft and a larger output shaft the size of a turbo 400 auto ******. the one that i had came from a 72 pontiac car and from what i have gathered on the internet they produced such a ****** from 72 all the way up to 76. corvette usage. the one i had also had the drain plug installed. so be careful and open it up and look at the gears to tell . hope this helps. hot rust
You need to look very closely at any Muncie for the common damage and wear to the syncro engagement teeth on the gears and sliding hubs.There are usually beat to **** making the gears on the mainshaft no more than s****.I believe the Italian M22 type gear sets are available in both close and wide ratio for less than 1000 bucks.
The only positive way is build your own. There are lots of web sites that sell parts and using the good Italian ge****t and steel case will set you back about $2K. If you decide to rebuild a stock Aluminum case, check it out very carefully. High HP and Bonzai shifts will deform the case and usually spreads the distance between shaft centers.
Got one of those too, also from a Pontiac. Thought the seller didn't know exactly what he had and figured out later it really was an M21, just like he told me. Learn something new every day and luckily it didn't cost me too much.
Gennie GM gears will have a 7 digit part # on them. aftermarket #s will start with a WT usually. And be in the format like this "WT 286-8A" on the cluster,this number is NOT a Muncie one just a sample.
This may be helpfull to some of you. http://www.nastyz28.com/chevy-manual-transmission-identification.php
All of the later Muncies (Early 70's and later) had the fine spline input and bigger TH400 output shaft, the drain plug was also used on non M22's of the same time period.
That is correct. The numbers are on the side of the gears, so some can not be viewed except by dismantling the trans. The picture below, you can so the number on the 2nd gear. This transmission is built with all Antonio Masiero ltd M22W gears from AutoGear in a M21 box. You can see the AM logo at the start of the part #. Jim
I thought about using an autogear trans or the like, and the ratio is probably better..however I really like the gear whine and am told that the italian ge****ts are so much better machined, they don't whine as much. So it comes down to using an older unit that may or may not need work, or an aftermarket unit which is much stronger and better built..and new, and quieter. I have tried to see before if anyone has actually heard one of the aftermarket units in person to tell me if that was true, but the words about that came from one of the companies that I asked about it. A couple of sites.. http://442restoration.homestead.com/files/muncie_4_speeds.htm http://www.fourgeartrans.com/id2.html http://www.tbtrans.com/muncie_4_speed.htm
You have to open them, you cant go by drain plugs, input shafts, tail shafts or case numbers. If it was a factory built trans you could go by the code but over the years rebuilders use whatever case is in the best shape. The early M-22's were course spline inputs and small tailshafts the late were fine inputs and large tail shafts. All late M-21's were also fine spline inputs and large tailshafts also, so like I said you have to open them up to be sure.
Dave's is the only answer. I must have destoyed a dozen ******s in the day. Wish they had the Italian gears back then.....
I concur, I have one of the transmissions. I have owned it for 25 years and as far as I know it has never been apart.
After rereading post one my reply really means nothing. But I will leave it just the same in the possiblity it may help someone that does not know how to tell a M20 M21 or M22 from one another with out opening it. Ratio Code Chart<?xml:namespace prefix = o ns = "urn:schemas-microsoft-comfficeffice" /><o></o>Letter: A M20 Ratio<o></o> Letter: B M21 Ratio<o></o> Letter: C M22 Ratio <o></o> <o>It's as simple as looking at the letter at the end of the serial # as shown above.</o>
Big power and big traction can break almost anything. I did that at Etown last time out. The trans is repaired and working well, but a new Severe Duty M-23 is coming in the near future.
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