[leeklm]

anyone have an iron Muncie 3spd for sale?

[Scott Thelander]

https://forums.maxperformanceinc.com...d.php?t=844084

[unruhjonny]

FYI:

The Muncie three speed, which is often confused with a saginaw three speed was Chevrolet only for 1969, then after used by all divisions;
it is most often found in trucks from 1969-1975(?)

Prior to 1970 the heavy duty three speed used in pretty much every Pontiac application I know if is a Ford sourced "Dearborn" unit.

they show up from time to time on ebay, and here's one right now:
1969 Muncie 330

Here is a thread I created to help identify them:

Muncie 330 Mc1/M13

I am ever keeping an eye out myself... and have yet to see if a lead i have will pan out (these border closures sure don't help me though).

[Bill Meyer]

Lee, I have some kind of three speed in my shop. Took it out of the gt37 27 years ago?... Give me a call... Bill

[leeklm]

Thank you for the information. I as well would get confused between the Iron Muncie 3spd vs the Dearborn unit as far as which Trans was used for the various years.. While I previously had the Muncie 3spd as OEM in my 73GTO, it sounds like the 66 GTO would have had the Dearborn trans?

What is the best way to ID the Dearborn trans vs the Iron Muncie?

[ROCKETMAN269V]

Originally Posted by leeklm

........What is the best way to ID the Dearborn trans vs the Iron Muncie?

The GM transmissions have the common symmetrical mounting ears sticking straight out, top and bottom; the Dearborn uses a Ford pattern, which is like a trapezoid, is wider at the bottom.

[400 4spd.]

Also, the Dearborn is a top-loader design, with the sheet metal access plate on top. I have two that I pulled from GTOs in the mid-70s.

[unruhjonny]

Originally Posted by ROCKETMAN269V

The GM transmissions have the common symmetrical mounting ears sticking straight out, top and bottom; the Dearborn uses a Ford pattern, which is like a trapezoid, is wider at the bottom.

Maybe I misundersttod RM's post, but I do believe that the Dearborn manual transmissions manufactured for OEM use in GM cars used the conventional GM bellhousing bolt pattern.

Here is a purported 1968 GTO/442 Dearborn unit;
You can see that this one doesn't have a typical ford mount.

EDIT: the last image is one with the Ford bellhousing mount.

[PontiacJim1959]

The Dearborn is a "top loader" as you can see in the photo. I assume the Muncie 3-speed would have a side opening case like the 4-speed?

The Pontiac bell housing has 2 bolt patterns. One pattern for the Muncie and Saginaw. The other is for the HD Dearborn (Ford) transmission. So this is why you will see the 2-bolt patterns on the bell. I can't speak for the other GM lines that used the trans.

The front bearing collar is the same diameter as the Muncie so it would fit the bell and I believe the input shaft is also changed for GM application. That was one of the differences between a Ford use Dearborn and a GM use Dearborn. I believe a couple other changes may have been incorporated for the GM use.

It is a very good HD transmission and will take the punishment. The disadvantage is the gear spread in not having the 4-speed. It is great if racing from a stop and rowing through the gears. But if you are traveling for example at 60 MPH, you aren't going to downshift into 2nd and give the would be racer a run for his money.

[unruhjonny]

Originally Posted by PontiacJim1959

... I assume the Muncie 3-speed would have a side opening case like the 4-speed?
...

yes, i posted links to assist anyone unclear on these transmissions in post #3

Here's a saginaw three speed versus a muncie three speed side cover comparison:

Originally Posted by unruhjonny

...
This is a saginaw three speed side cover (notice the top/centre bolt boss):



This is a 1969-1976(?) Muncie three speed side cover (notice the two off centre bolt bosses):


...

[PontiacJim1959]

Originally Posted by unruhjonny

yes, i posted links to assist anyone unclear on these transmissions in post #3

Here's a saginaw three speed versus a muncie three speed side cover comparison:

Good pics. Have personally never seen a Muncie or a Saginaw 3-speed in my dealings with old cars - just Muncie, Dearborn, and automatics. Thanks.

[ROCKETMAN269V]

Originally Posted by PontiacJim1959

............ I can't speak for the other GM lines that used the trans.......

My '68 Cutlass, with 35,000 miles on it, that I purchased from the original owner, had a factory 3-speed floor shift, had the Dearborn trans with the dual bolt pattern on the bellhousing. I believe that the bolt pattern on those trans' was rotated a number of degrees to discourage interchanging with Ford applications.