Trans ?'s
Thread Starter
Instructor
Joined: Jun 2008
Posts: 173
Likes: 1
From: Central Iowa
Trans ?'s
I have my trans out of the car(73 454 4sp) and need to get it rebuilt. The numbers on the case are 3925661. I just need to know what it is so i can be sure to get the right parts coming for it when i know what's wrong. 
Thanks
Thanks
Thread Starter
Instructor
Joined: Jun 2008
Posts: 173
Likes: 1
From: Central Iowa
where the hell are these letters? 
The numbers on the back towards the output shaft are 3978764. unless i'm missing reading or the letter is warn off the last "1" could be an A depending on where the letter's are placed.
The numbers on the back towards the output shaft are 3978764. unless i'm missing reading or the letter is warn off the last "1" could be an A depending on where the letter's are placed.
Race Director
Joined: May 2006
Posts: 18,665
Likes: 2,564
that's the casting number for the tailhousing not the transmission, check this link
http://www.5speeds.com/casting.html
http://www.5speeds.com/casting.html
Racer
Joined: Dec 2008
Posts: 297
Likes: 19
From: arlington TX
Hi,
If you go to the link above, click on the "click here for info" at the top. It brings up some pics. The top left pic shows a stock and an "improved" case. On the stock case, on the flange at the back where the tailshaft bolts up, is a stamped (not cast) number. On a "numbers matching" tranny (original), that stamped number will be part of the vin and the letters that tell what tranny it is - M20, M21, M22. Hope that helps.
walt
If you go to the link above, click on the "click here for info" at the top. It brings up some pics. The top left pic shows a stock and an "improved" case. On the stock case, on the flange at the back where the tailshaft bolts up, is a stamped (not cast) number. On a "numbers matching" tranny (original), that stamped number will be part of the vin and the letters that tell what tranny it is - M20, M21, M22. Hope that helps.
walt
Thread Starter
Instructor
Joined: Jun 2008
Posts: 173
Likes: 1
From: Central Iowa
Alright i was finally able to clean her off good and find what you guys are talking about. It's the letter "B" so now i know what i'm looking for. Thank you guys so much for the help. Now time to build her up and get it back on the road.
Thread Starter
Instructor
Joined: Jun 2008
Posts: 173
Likes: 1
From: Central Iowa
http://www.5speeds.com/muncie2.htm
according to this my casting number should be "3925661" and my number on my trans i could have sworn it was "3978764" so what does that mean?
Also how do i know if it's a wide ratio or close ratio M21?
Thanks!
according to this my casting number should be "3925661" and my number on my trans i could have sworn it was "3978764" so what does that mean?
Also how do i know if it's a wide ratio or close ratio M21?
Thanks!
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Melting Slicks
Joined: Sep 2004
Posts: 2,655
Likes: 19
You'll need to check the input shaft for the number of rings.
Or you could remove the side cover and try to count gear teeth number (not easy).
Or you could put it in first, crank the engine over 1 revolution by hand and cont the number of driveshaft revolutions (2.2 or 2.5)
Or you could remove the side cover and try to count gear teeth number (not easy).
Or you could put it in first, crank the engine over 1 revolution by hand and cont the number of driveshaft revolutions (2.2 or 2.5)
Thread Starter
Instructor
Joined: Jun 2008
Posts: 173
Likes: 1
From: Central Iowa
I guess i also need some advice on what i should do. I busted up the teeth on the top long set of gears as well as the lower solid unit. And in doing so i took out a chunk towards the rear of the case and my trans guy said i may need to look into just buying a new trans cuz he couldn't gaurantee how long it would last if i wear to be "hard on it"
So i guess i'd like some insite on what you guys think i should do. Should i just order another 4sp to put in there and rebuild the number's matching one and put it in the corner in plastic? Or should i try to put a 5sp in there? or is there anyone out there that is running a 5sp and had troubles doing so? the car is going to be my nice evening/sunday cruiser so no long road trips.
So i guess i'd like some insite on what you guys think i should do. Should i just order another 4sp to put in there and rebuild the number's matching one and put it in the corner in plastic? Or should i try to put a 5sp in there? or is there anyone out there that is running a 5sp and had troubles doing so? the car is going to be my nice evening/sunday cruiser so no long road trips.
Burning Brakes
Joined: Jan 2012
Posts: 943
Likes: 73
http://www.5speeds.com/muncie2.htm
according to this my casting number should be "3925661" and my number on my trans i could have sworn it was "3978764" so what does that mean?
Also how do i know if it's a wide ratio or close ratio M21?
Thanks!
according to this my casting number should be "3925661" and my number on my trans i could have sworn it was "3978764" so what does that mean?
Also how do i know if it's a wide ratio or close ratio M21?
Thanks!
Melting Slicks
Joined: Sep 2004
Posts: 2,655
Likes: 19
If you busted gears and damaged the case, you probably stretched it between the input and countershaft holes. Rebuilding with the original case will probably fail.
If you have a relatively low rear end ration, 3,08, 3.31 etc and you're on a budget, buy an upgraded muncie with supercase and upgraded midplate. If you've got a high rear rear end and some extra cash, go for an OD Richmond or Tremec.
Btw it's the number of rings around the input that tell close vs wide.
http://www.5speeds.com/muncie2.htm
If you have a relatively low rear end ration, 3,08, 3.31 etc and you're on a budget, buy an upgraded muncie with supercase and upgraded midplate. If you've got a high rear rear end and some extra cash, go for an OD Richmond or Tremec.
Btw it's the number of rings around the input that tell close vs wide.
http://www.5speeds.com/muncie2.htm
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
http://www.5speeds.com/muncie2.htm
according to this my casting number should be "3925661" and my number on my trans i could have sworn it was "3978764" so what does that mean?
Also how do i know if it's a wide ratio or close ratio M21?
Thanks!
according to this my casting number should be "3925661" and my number on my trans i could have sworn it was "3978764" so what does that mean?
Also how do i know if it's a wide ratio or close ratio M21?
Thanks!
Thread Starter
Instructor
Joined: Jun 2008
Posts: 173
Likes: 1
From: Central Iowa
Are there any issues as far as fitting goes with the richmond 5 speeds or tremec? Will it bolt up with my bellhousing and the crossmember just right? And does anyone recomend a shop to purchase one of these units?
Melting Slicks
Joined: Aug 2008
Posts: 2,200
Likes: 3
From: Lehigh county Pennsylvania
And circumferential rings machined on the input splines are only on factory installed input shafts.
Last edited by 69 Chevy; Apr 14, 2012 at 11:36 AM.
Melting Slicks
Joined: Sep 2004
Posts: 2,655
Likes: 19
Melting Slicks
Joined: Sep 2004
Posts: 2,655
Likes: 19
No interior mods. If you buy a 67 hurst shifter handle, it will even look like the Muncie inside.
If you have a non-removable crossmember, cut it!!!! I did mine with the crossmember in place, what a pain....live and learn. Hell I think I would cut it out even if I was swapping for another Muncie.
The muncie is mounted to tongue that extends forward of the crossmember. The Richmond will sit just forward of the crossmember without the tongue and needs to be lowered. I've seen pics of modding the crossmember putting the mount about 1/2" lower. Easy to do with the crossmember out. I just made a rubber trans mount that was 1/2" shorter than stock since my crossmember was still in place.
I've got pics somewhere if you're interested.
If you have a non-removable crossmember, cut it!!!! I did mine with the crossmember in place, what a pain....live and learn. Hell I think I would cut it out even if I was swapping for another Muncie.
The muncie is mounted to tongue that extends forward of the crossmember. The Richmond will sit just forward of the crossmember without the tongue and needs to be lowered. I've seen pics of modding the crossmember putting the mount about 1/2" lower. Easy to do with the crossmember out. I just made a rubber trans mount that was 1/2" shorter than stock since my crossmember was still in place.
I've got pics somewhere if you're interested.