Muncie Recommendations

[mabeauchamp]

I am in the process of converting my 62 ss QG car to a 4 speed. Does anyone have an recommendations on a 4 speed. I was thinking of an M20 as it will work well with the 3.70 posi I plan to run and it should giddy up off the line. Any thoughts. Also, does anyone know a reputable shop that a rebuild one can be ordered from?

[CDNpontiac409guy]

I'd pass on the Muncie altogether. Unless it's a restoration of a LATE 63-72 GM, the Muncie has no "special qualities".
Simply locate a 76-81 Z28 Camaro Borg Warner Super T10 ( 2.64 1st gear... "3 rings on input ). You can use the Camaro's flywheel, clutch assembly and bell housing as well. You WILL need the early Chevy release fork.

The Super T10 is stronger, and has a better 1st gear. Also, you COULD buy a brand new Richmond T10 ( a re-make of the BW ). They're about $1400... available in a vast assortment of gear ratios.

[chev1960]

Your right Aubrey ,I just did what you say last year 0n my 1960 biscayne 2 doors 409 4 speed , except the trans was a saginaw ,and it work just find ,I just ad to cut the front drive shaft a bit , and safe me a lot of money and I think more dependable.
chev1960

[Garbageman]

I agree that the old Muncie's can be trouble-some. I went through three of them in my "62. They didn't seem to hold up on the dragstrip. :bang

But....

I found a shop in Spokane, WA that puts together a strong M22. T&B Transmission uses the new Autogear main case that is a lot stronger than the old production unit. I bought mine in 2002 and it hasn't given me a bit of trouble. The M22 cost , at that time, $1450.00 with a trade core and it was $36.00 to UPS it to me. :D

I strongly recommend T&B Transmission, they even warranty the transmission for 6 months and Tom is real easy to deal with.

Paul

[Tony Salins]

I ran a M-21 in my 62 from 1972 to 1979 and raced the car every weekend that the track was open. I beat the H*** out of it and the trans stayed together. The only problem I had with the trans was I pulled the boss out of the side cover once. Of coarse the sychronizers needed to be replaced a couple of times but that's just maintenance. Back then my 62 was a consistent 12.90 car.

I also believe that a Super T-10 is stronger but it's also more money.

[oil4kids]

Anyone have experience with the cast iron 4 speed saginaws? strong? weak?-

[Dond409]

I had one in a 67 camaro with a 327, 2 barrel carb. Changed the cam to a 350hp hyd. added a quadrajet 4bbl manifold. 2 days later the tranny was junk. :bang

[threeimpalas]

I have a 4 speed Saginaw behind a 468 BBC in the '61 wagon. It's held up fine so far and seen some "spirited" driving; no drag racing, though. They'll hold up fine if you don't drive like a bat out of hell all the time. The nice thing about them is you can go through quite a few before you reach the cost of a Muncie or T10.

[Mr Goodwrench]

While on the subject of 4 speed, had a guy call me about what he says is a 1962 t-10. because it has an aluminum case he thinks it's a 409 tranny and worth big bucks? I'm no expert but I thought like the munchie's they all were aluminum case??? :dunno what about the going price these days on t-10's or munchies (cause we used to munch them up) excepet for the guys piecing together a number matching car I didnt think the value was that high, $400,00 range.

[SteveD409]

1961 model year-aluminum in Corvettes and 409 cars, all others cast iron. 1962 all were aluminum. That's what I've always been told. But I've been wrong before! :)

All prior to 61 were cast iron cased.

[Skip FIx]

My old 64 with its Muncie new had a problem and ALOT of 6000 side steps. But they can break and alot of my Pontiac buddies have broken them.

There is a place selling new cases and other HD parts. I'll see if I can find the source. I think they do have a web site.HD gears are also available. I think LibertyGear even makes straight cut gears to put in them.

For a spirited 409 especially if more race oriented, a Jerico is the only way to go.

[mabeauchamp]

its sounding as though the muncie is not quite what i thought it was. growing up these things had a bad xxx (meaning good) reputation. based on the my current rebuild i'm hoping for 360-370 hp for my 409. i reusing the low performance heads, increasing the compression, and hopping up the cam. would i be better off to go with a jerico or is that overkill?

[walkerheaders]

get a nice m-20 if you can get a decent deal. you'll be so fine, with a 409 and muncie whine. if you take care of it, it'll last as long as the car. a jerico is $4000 i saw an m-20 last week for $500 if you are gonna use no less than a 3.70 ratio, you can even use an m-21 with 2.20 low. any of the transes these guys recommended are good. just look for a deal that includes all the parts you'll need.

[Skip FIx]

The Muncie will probably be OK with a fairly street car,but check the rest of the drivetrain also. Mine held up with the 6000 side steps running 12 .20 @ 108 in 1972. The rearend broke first also a driveshaft spline. It did have an aluminum flywheel that was a little easier also.

[droptop62]

Some of these HARD CORE types are trying to make the Muncie 4-speeds look bad.
If you plan on doing some serious drag racing and really abusing your car, then you may want to take the advice of the serious drag racers (above).
for a street driven car with some occaisional track time the muncie will be fine.

[chev1960]

I have a 1960 biscayne 2doors with a strong 409 and I put a 4 speed Saginaw 7months ago ,ad a couples of good tires burn since and I mean real good tires burn ,and the 4 speed Saginaw still work strong no problem yet ,only 2 sets of rear tires change .
1960chev

[models916]

Back in 69 I used to break the shifter forks in my saginaw 4 sp nearly once a month. I switched to a Muncie M21 with no further problems. Car was about 400 hp, 536 posi, 3400 lbs., 7 inch slicks. Ran low 12's. You got to figure once you stop the trans from breaking other drivetrain problems will happen.

[oil4kids]

Thanks for the feedback on the saginaw, this transmission raises many questions, some seem to hold up and soom seem to fly apart- maybe its a quality control issue of the metals that were used during manufacturing, I also thought that the saginaw trans division made the muncie type trans under license(maybe Fran can answer this)


As far as the M21, my brother had one in a 67 GTO 400/360hp which he continously beat on the street and the drags and sold it with over 100k miles without touching the trans, syncros or gear oil. It was a bone stock high 13.95s car. Maye the only thing that saved the trans were the Firestone 500 tires which never really hooked up very well. Now that i think of it, the Casler slicks didnt work too well either.

[SteveD409]

Never heard of any "Muncies" being biuilt in Saginaw. Thought all were made by Chevrolet Transmission Division here in Indiana. The T10's were also all made in Muncie at Warner Gear, a division of Borg Warner. I would really be interested if anyone can substanciate Saginaw making any M20-22s.

SteveD

[jim_ss409]

Gm used to put Saginaws in the lower HP cars and I know they aren't as strong as a Muncie. But they seem to be fine for everyday use and they have a lower first gear, which is nice. The lower first gear might contribute to the Saginaws reputation for weakness. I've noticed that the torque ratings on a Richmond T-10, which I think is basicly a Super T-10, are not as high on the models with the lower first gear. It's also surprizing just how low the torque ratings are. I think they're being a bit conservative. http://www.richmondgear.com/01pdfs/pages33-35.pdf From what I can gather about GM transmissions I'd rate them like this... Starting with the weakest and working to the strongest...
Saginaw
T-10 Wide Ratio
T-10 Close ratio
Muncie M-20 (wide)
Muncie M-21 (close)
Super T-10 Wide
Super T-10 Close
Muncie M-22 (Rockcrusher)
Super T-10 with replacement GM iron case.

This is just my guess. I just thought I'd throw this out to see if others agree or dissagree. :D

[oil4kids]

The 4 speed sags come with different first/ 2nd/3rd gear rations depending on how may bands were cut on the input shaft


Saginaw 4-speed 1st 2nd 3rd 4th

No lines 2.84 2.01 1.35 1.00
1 Line 2.54 1.80 1.44 1.00
2 Lines 3.11 2.20 1.47 1.00
3 Lines 3.50 2.47 1.65 1.00 (probably for trucks )


the good thing about this trans is that you can bolt on the overdrive from the 3 speed onto the 4 speed box with a little drilling.

also


Maincase Gear Ratios Input Grooves Cluster Output
RPO Years Casting 1st 2nd 3rd 4th Spline (Input) Pin Spline
-----------------------------------------------------------------------
Muncie
M20 63-65 3851325 2.56 1.91 1.48 1.00 10 None 7/8-inch 27
M20 66-67 3885010 2.52 1.88 1.46 1.00 10 2 1-inch 27
M20 68-69 3925660 2.52 1.88 1.46 1.00 10 2 1-inch 27
M20 70 3925661 2.52 1.88 1.46 1.00 10 2 1-inch 27
M20 71-74 3925661 2.52 1.88 1.46 1.00 26 2 1-inch 32

M21 63-65 3851325 2.20 1.64 1.28 1.00 10 1 7/8-inch 27
M21 66-67 3885010 2.20 1.64 1.28 1.00 10 1 1-inch 27
M21 68-69 3925660 2.20 1.64 1.28 1.00 10 1 1-inch 27
M21 70 3925661 2.20 1.64 1.28 1.00 10 1 1-inch 27
M21 71-74 3925661 2.20 1.64 1.28 1.00 26 1 1-inch 32

M22 65 removed 2.20 1.64 1.28 1.00 10 None 1-inch 27
M22 66-69 3925660 2.20 1.64 1.28 1.00 10 None 1-inch 27
M22 70 3925661 2.20 1.64 1.28 1.00 10 None 1-inch 27
M22 71-74 3925661 2.20 1.64 1.28 1.00 26 None 1-inch 32

Saginaw
M20 6-cyl 3.11 2.20 1.47 1.00
M20 V8 2.54 1.80 1.44 1.00