Author Topic: 69 Muncie Transmission tag (pn?)  (Read 17641 times)

z28z11

  • Hero Member
  • *****
  • Posts: 1853
    • View Profile
Re: 69 Muncie Transmission tag (pn?)
« Reply #15 on: May 09, 2014, 02:09:21 AM »

Based on bcmiller's post below, were different PN's used on Muncies based on the *rear end ratio*??  Why would they do that??
(I'm trying to learn my 'Camaro new information for the day'...  :)

Because each different rear end ratio required a different plastic (I think) gear to make the speedometer read correctly.

Actually, the plastic DRIVEN gear was installed at the car assembly plant. What changed was the internal steel DRIVE gear that was pressed on the output shaft at Muncie;

Actually not pressed on, the gear slips over the tail end of the mainshaft and is secured by a spring steel clip. How do I know ? My '69 Z M20 clip broke, lodged in the reverse gear, and jammed the transmission. I made it to the station I worked at, pulled the trans and found the problem. New clip and back in business. Earlier Muncies pressed on -  
« Last Edit: May 09, 2014, 03:15:22 AM by z28z11 »
1968 Z28 M21/U17 BRG/W 1967 Chevy ll Nova SS 
1969 Z28 X77/M20/VE3 LeMans/W
1969 L78 X66/N66 Cortez/BVT
1969 Z11 L48/M35/C60/C06  1949 3100 5wd 235/6

JohnZ

  • CRG Member
  • *****
  • Posts: 4365
    • View Profile
Re: 69 Muncie Transmission tag (pn?)
« Reply #16 on: May 09, 2014, 05:28:26 PM »

Based on bcmiller's post below, were different PN's used on Muncies based on the *rear end ratio*??  Why would they do that??
(I'm trying to learn my 'Camaro new information for the day'...  :)

Because each different rear end ratio required a different plastic (I think) gear to make the speedometer read correctly.

Actually, the plastic DRIVEN gear was installed at the car assembly plant. What changed was the internal steel DRIVE gear that was pressed on the output shaft at Muncie;

Actually not pressed on, the gear slips over the tail end of the mainshaft and is secured by a spring steel clip. How do I know ? My '69 Z M20 clip broke, lodged in the reverse gear, and jammed the transmission. I made it to the station I worked at, pulled the trans and found the problem. New clip and back in business. Earlier Muncies pressed on - 

Yup - the nylon DRIVE gear and spring steel retainer started in '68.
'69 Z/28
Fathom Green
CRG

Bryan302

  • Member
  • ***
  • Posts: 179
    • View Profile
Re: 69 Muncie Transmission tag (pn?)
« Reply #17 on: May 27, 2015, 05:32:58 AM »
I'm in the process of rebuilding / restoring my M21.  I'm to the point of refinishing the bolts and the 3946798 part number tag and wanted to find out what finish the part number tag was originally?  Was it natural bare steel and painted or zinc plated?

Thanks,
Bryan
Bryan S.
1968 RS Z/28, 12E, PNT R2, TR 749
1969 Z/28 X33, 05A, PNT 52 52, TR 719, endura bumper

ko-lek-tor

  • Hero Member
  • *****
  • Posts: 1858
  • someday I'll get one finished
    • View Profile
Re: 69 Muncie Transmission tag (pn?)
« Reply #18 on: May 27, 2015, 12:00:49 PM »
I'm in the process of rebuilding / restoring my M21.  I'm to the point of refinishing the bolts and the 3946798 part number tag and wanted to find out what finish the part number tag was originally?  Was it natural bare steel and painted or zinc plated?

Thanks,
Bryan
Bryon, I am going to stick my neck out, based on my observations over the years and, think about it, these tags were for the line workers to ID a trans, why would they (Muncie Div., GM) require paint or plating (adding uneccessary costs)? So, I have only observed plain unpainted/ unplated steel stamped tags and I am sure that is how they came. B.
Bentley to friends :1969 SS/RS 396 owned 79
1969 SS 350 (sold)
1969 D.H.COPO replica 4spd. owned since 85
1967 302 4 spd 5.13

69Z28-RS

  • Hero Member
  • *****
  • Posts: 5778
  • owner since 4-Apr-1976
    • View Profile
Re: 69 Muncie Transmission tag (pn?)
« Reply #19 on: May 27, 2015, 12:24:41 PM »
I'm in the process of rebuilding / restoring my M21.  I'm to the point of refinishing the bolts and the 3946798 part number tag and wanted to find out what finish the part number tag was originally?  Was it natural bare steel and painted or zinc plated?

Thanks,
Bryan
Bryon, I am going to stick my neck out, based on my observations over the years and, think about it, these tags were for the line workers to ID a trans, why would they (Muncie Div., GM) require paint or plating (adding uneccessary costs)? So, I have only observed plain unpainted/ unplated steel stamped tags and I am sure that is how they came. B.

I'm usually with Bentley, and I am here as well... I've never observed any traces of paint or plating on those tags; most are covered in light rust when going untouched.  Suggestion:  evaporust and then a light coast of satin clear should preserve it looking 'new' for a long while.. :)
09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette, '60 Corvette, '72 Corvette
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

bcmiller

  • CRG Member
  • *****
  • Posts: 4004
    • View Profile
Re: 69 Muncie Transmission tag (pn?)
« Reply #20 on: May 27, 2015, 01:56:07 PM »
We have agreement.  Those metal tags were natural metal, not painted or plated.   :)
Bryon / 1968 Camaro SS 396 coupe - now old school 468 big block
1967 Camaro RS/SS 396 coupe L35/M40 - 4 generation family project
Looking for 68 Camaro with body # NOR 181016

Bryan302

  • Member
  • ***
  • Posts: 179
    • View Profile
Re: 69 Muncie Transmission tag (pn?)
« Reply #21 on: May 28, 2015, 07:41:34 PM »
Thanks for the input.  I just had to ask.  If they had been plated, one would have never known, mostly because of where they were located, and the exposure to the elements.  Bentley had a very good point.... Why would they have plated them?  That made very good sense.  So, bare metal with a light clear it will be.

Thanks,
Bryan
Bryan S.
1968 RS Z/28, 12E, PNT R2, TR 749
1969 Z/28 X33, 05A, PNT 52 52, TR 719, endura bumper

lynnbilodeau

  • Member
  • ***
  • Posts: 395
    • View Profile
Re: 69 Muncie Transmission tag (pn?)
« Reply #22 on: June 09, 2015, 12:54:34 AM »
According to the AIM

3950356  N29 for L48, L34, L35 & LM1
3946797 M20 for Z/28 or L78 (and also COPO although not listed in the AIM)
3950316  M21 for L34
3946798  M21 for Z/28 or L/78 (and also COPO although not listed in the AIM)
3950318  M22 for Z/28 or L/78 (and also COPO although not listed in the AIM)

And I agree, tags were not painted.   But I painted mine just because I didn't want it to rust.

 

anything