Muncie M-21 transmission questions

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will_powerless - 21 Oct 2006 05:19 GMT

Have a decent '62 Chevy BelAir with a 6-cylinder and 3-speed.
Contemplating a small block chevy and 4-speed swap in the Spring.
Someone else will be assisting but when looking for an M-21 4-speed,
are there particular points to look for? Spline count on input or
output shafts? Input/out shaft lenghts? Do these things vary? Engine
will probably be a pre-'86, but conceivably may be a new crate engine.

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willy - 21 Oct 2006 07:49 GMT

> Have a decent '62 Chevy BelAir with a 6-cylinder and 3-speed.
> Contemplating a small block chevy and 4-speed swap in the Spring.
> Someone else will be assisting but when looking for an M-21 4-speed,
> are there particular points to look for? Spline count on input or
> output shafts? Input/out shaft lenghts? Do these things vary? Engine
> will probably be a pre-'86, but conceivably may be a new crate engine.

The M 20 and M 21 are the same spline count and are a course spline
input shaft.All three are aluminum hosings. The M 22 is a fine spline
input shaft. All three are the same on the outside. The easiest and
fastest way to tell the difference between the three is, look it the
input shaft. A M 20 will "not" have a circler groove around the input
shaft, approx. mid sahaft and 1/8" wide. A M 21 "will" have "one
groove" around the input shaft. A M 22 will have "two grooves" around
the input shaft, and a fine spline input shaft. The M 22, (known as "A
Rockcrusher"), has different gear ratio's. The M 22 is the best out of
the Muncie family. I've had all three and have some left. Their nice
transmission's, when all the brass sycronizers are good and their not
put together to tight. They are not a very bullet proof or very miss a
shift friendly. The Borg Warner T 10 is probably better, but they are
bigger then the Muncie and don't give ya alot of room in the tunel,
where as the Muncie is a nice compact, descent trans. The cast iron
pigs where more bullet proof. And cheaper to buy/repair. Ifin your
makin a "Cruiser", automatic/O.D. is the way to go. Ifin you gotta have
a stick, go with a 5 speed.

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Nate Nagel - 21 Oct 2006 12:23 GMT

>>Have a decent '62 Chevy BelAir with a 6-cylinder and 3-speed.
>>Contemplating a small block chevy and 4-speed swap in the Spring.
[quoted text clipped - 21 lines]
> makin a "Cruiser", automatic/O.D. is the way to go. Ifin you gotta have
> a stick, go with a 5 speed.

I kind-of agree with the statements above, with the caveat that for a
really hot motor you have to be careful what 5-speed you pick. I have a
Studebaker which is a fairly torquey engine and I've been told that most
5-speeds are not strong enough to stand up behind a stump puller engine
driven hard (and what's the point of having a 5-speed if you're not
going to bang gears?) Supposedly a "world class" T5 is marginal but the
new Tremecs are the way to go; unfortunately they are still pricey while
I can find old T-10s for a couple hundred bucks, so guess what my car
has in it... However, I only stuck with a T-10 because that was stock
for Studebaker and therefore required less work to make it fit; by all
reports a Muncie is at least as strong.

nate

Signature

replace "fly" with "com" to reply.
http://home.comcast.net/~njnagel

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Stan Weiss - 21 Oct 2006 15:23 GMT

> >>Have a decent '62 Chevy BelAir with a 6-cylinder and 3-speed.
> >>Contemplating a small block chevy and 4-speed swap in the Spring.
[quoted text clipped - 39 lines]
> replace "fly" with "com" to reply.
> http://home.comcast.net/~njnagel

The T-45 (Tremec) used in v8 Mustangs to mid '01 has Torque cap. of 325
lbs-ft and the 3650 used from mid '01 on has a torque cap. of 360
lbs-ft. See web site for full line and torque cap.
http://www.ttcautomotive.com/English/products/tremec.asp
Stan

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N8N - 21 Oct 2006 17:15 GMT

> > >>Have a decent '62 Chevy BelAir with a 6-cylinder and 3-speed.
> > >>Contemplating a small block chevy and 4-speed swap in the Spring.
[quoted text clipped - 45 lines]
> http://www.ttcautomotive.com/English/products/tremec.asp
> Stan

I was actually thinking of the TKO500, apparently that is starting to
become a popular swap into a Stude (well, as popular as *anything* for
a Stude can be.) A standard 289 was rated at something like 300 ft-lbs
in stock trim, so this is a real concern. Granted, that's gross not
net, but still.

The gear spread looks awesome too, even the "close ratio" provides more
gear spread 1-4 than a "wide ratio" T-10; I could probably go with a
close ratio TKO and keep my 3.73:1 rear and get a deeper first gear and
still have comfortable cruising. I wanna spend money...

nate

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Stan Weiss - 21 Oct 2006 19:14 GMT

> > > >>Have a decent '62 Chevy BelAir with a 6-cylinder and 3-speed.
> > > >>Contemplating a small block chevy and 4-speed swap in the Spring.
[quoted text clipped - 58 lines]
>
> nate

My 2000 Mustang GT has the 4.6l and is rated at 302 lbs-ft. It has
(stock T-45) 3.37 1.99 1.33 1.00 0.67 gearing and a 3.27 rear with the
optional 17" wheels and 245-45-17 tire it is turning 2000 RPM at 70 MPH
in 5th.
Stan

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