Hi, everyone. Thanks so much for letting me onboard. If I’m posting this thread in the wrong place, please accept my apologies and let me know where it belongs. I might be buying my late father’s 1965 Chevelle SS (327 motor) back from the estate. Unfortunately, he let the original 4 speed trans go with another Chevelle SS decades ago (that one had a big block). The deal was that when he found a replacement trans (presumably an M22), the buyer would swap him back so that his would have all matching numbers. Now that my dad has p***ed, the guy is spinning a different tale and wants the rebuilt Muncie for free. So long story short, there are currently two Muncies here that I’m trying to identify, in order to determine if either will mate up to the 327. Since it’s already a confusing story, I’ll just mention the first one here, in hopes that someone can help me identify it. I’m far, far, far from an expert, but I do realize that you really need to open one of these babies up in order to get a fully accurate identification. I’ll be tied up trying to settle Probate for a few more months, so I’m hoping to just get to a starting point. So here’s what I know about Muncie Trans #1. It’s supposedly rebuilt and did have a trans shop tag on it when I found it. The input shaft has 10 splines, with 2 rings. I tried to count the output splines without my gl***es and came up with 23 (which I know isn’t a thing). I found the following numbers on it: GM 3885010 Patent 3088336 7B215617 Based on the fact that the input shaft has 10 splines and 2 rings, I would guess that it’s not an M21. Since the history would indicate that it was intended to mate up to a different Chevelle with a big block, my ***umption is that it could be an M22, but the info I see online seems to conflict with this. Production date information also varies from site to site, so I’m pretty lost. Could anyone who actually knows these transmissions possibly help me to identify it? Thanks so very much, guys.
A complete pic of side where leaver arms go, Yes you can mate both trains to 327 & Gm bell , match input splines to clutch disc I'm Not for sure, both 21/22 are pricey on replacement parts, m21 small out put shaft like glide /350 m22 big out put shaft like 400 Someone will post here shortly to better identify what you have & identification
Hey, Johnny. Funny you sent this link, given that it’s the chart I consulted first. Both of the Muncies on the property have 10 splines and two rings on the input shaft. According to the chart, the only one that would have this combo is the 1966-70 M20. Which is odd, since the two look rather different and have different serial numbers (3885010 vs 3925660 - both with patent #3088336). Again, I totally do not consider myself a mechanic, despite always having done all my own work on my cars for over 35 years. I’m a wrencher, but not a gearhead. But am I missing something obvious? Thanks.
I had a M21 HD in my LT-1 vette that had the T400 output shaft and one drain plug. Of course, I drilled out the other plug cuz why would you not?
With the ability to mix & match parts , its nearly impossible to know what you have , I've used parts from various transmissions to put one together . If Mr. Peabody wants a Muncie , give him what he wants , m22 are rare & often mid identified .
010 case is late1965-1967, 660 case is 1968-1970, both should be 1" counter bore. Although I have seen one 010 case in a very early production 1968. Quite possible both transmissions could be a mix and match of cases, side covers and tail housings. They could have been rebuilt numerous times, over the years. Bill
010 cases did not come out till 1966, 64-65 were 325, which is what your dad's Chevelle would have. I'm not really following what you are trying to do; get the original back or find a replacement that will work?
2 ring input is a M20 wide ratio. A 1966-67 010 cased M22 would be exceptionally rare. The M22 didn't have any rings on the input shaft and they are close ratio. They didn't do the fine spline input, turbo 400 style output till 1970. The 70 and later trans had a 661 case. Of course things can get swapped around, im just relaying what they came with originally. Sounds like you have 2 wide ratio, M20 Muncie transmissions. Those were the most common.
Can't always rely by serial number (VIN) stampings to ID The Kansas ***embly plant was notorious for not stamping serial numbers on all Muncie's. Some had them on the side by the Muncie production numbers, some on the top rear of main case by the mid plate and some not at all. Bill
7B215617 would indicate a partial vin. 7 being 67, B Baltimore ***embly plant and 215617 the last of the vin. It was that way with my original matching numbers Chevelle. It had an M-20 wide ratio. Pat
All of the number stampings are really only relevant if you are trying to determine if its numbers matching to the cars VIN. Then if numbers are matching to the case, the side cover and tail housing could be miss-matched, wrong casting numbers or not matching date codes. Bill
Yep The M20 in my 67 Nova is what I call a "drum" Muncie, I had one ***embled in the early 80's by a guy that relocated his transmission shop and he had all his major used parts stored in 55 gallon drums. The main case is a 69, tailhousing and side cover are 66, did this so I could use the earlier style shifter that uses stud/nut style shift shafts.
It does...the little shoulder of the shift lever are slightly different sizes. You'll see Hurst installation kits for Muncie and there are two type 451 Muncie 1963 to 68..and type 452, 1969 and later. The only difference is the size of the hole in the arm that fits on the proper year trans (side cover). The 1969 and later style shift lever where the shifter arm attaches is slightly larger.
As has been already said, it is a 66-67 010 main case and side cover with a 64-early 65 tail housing with the L.H. speedo gear. It will have the 1" counter shaft. It is a wide ratio with a 2.52:1 lowgear. 1969 was the first year for the female shift shaft holes.
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