1966 GT350 rear axle tag DSO C6ZX-C from 6S1585

[6s1640]

Hi all,

Attached is an image of the rear axle tag from 6S1585.  The 2011 registry shows the "926" as the "Plant Code".  Will all the tags for 1966 GT350 (post 6S252) have this same code?  I could not find any info on the plant code.  Please advise.

Thanks

Cory

[Bob Gaines]

The 926 is not the plant code is why you can't find it . The 926 has more to do with the rear axel ratio . It is different number on 4 speeds. Although I have never seen a intact rear end housing axel tube paper sticker on 66 GT35's I have seen a multitude on 67-70 . That same number series that is on the tag shows up on the paper tag wrapped around the axel tube of the 67-70 depending on that 3 digit code that is on the metal tag. That makes me think it has to do with housing ,ratio and backing plate assembly. At least that is what I think it has to do with at this point. It is just a theory until more positive evidence suggest otherwise.

[6s1640]

Hi Bob,

I had not idea on the 926 code.  I was following the 2011 registry.   I think you have something.  I think "Plant Code" must mean the code used by the "manufacturing plant" to identify the setup, not the plant itself.  Dead Nuts On has a chart for 68-71 codes that have similar type numbers.  See attached link.

Thanks

Cory

https://www.deadnutson.com/rear-axle-paper-id-tags/

[J_Speegle]

The 926 is not the plant code is why you can't find it . The 926 has more to do with the rear axel ratio . It is different number on 4 speeds. Although I have never seen a intact rear end housing axel tube paper sticker on 66 GT35's I have seen a multitude on 67-70 . That same number series that is on the tag shows up on the paper tag wrapped around the axel tube of the 67-70 depending on that 3 digit code that is on the metal tag. That makes me think it has to do with housing ,ratio and backing plate assembly. ..........................

+1 Believe we will find it identifies the complete assembly and would match the numbers located on the buildsheet also if these cars had the later style buildsheets like the 67+

There are a couple of different versions of the information on the tags of 66 GT350's Early versions don't have the numbers there but "SP" instead

Examples

[6s1640]

Hi Jeff,

Thanks for jumping in.  The tag with 925 has the 3.89:1 ratio, four speed car.  So does 925 include four speed?  The tag from 6S1585 is an automatic car with the 3.50:1 rear axle.  Does 926 include automatic?

Thanks

Cory

[Bob Gaines]

Hi Jeff,

Thanks for jumping in.  The tag with 925 has the 3.89:1 ratio, four speed car.  So does 925 include four speed?  The tag from 6S1585 is an automatic car with the 3.50:1 rear axle.  Does 926 include automatic?

Thanks

Cory

Cory, your picture of a tag is for a automatic car because it is a 3.50 ratio. 3.50 is the typical factory rear end ratio for a 66 automatic GT350. 926 appears on other 3.50 tags so logically that goes along with the ratio. The same goes with 925 and 4 speed 66 GT350's.  6S1585 is built late enough in production that it is not surprising that the tag in the picture is for your car.

[J_Speegle]

Hi Jeff,

Thanks for jumping in.  The tag with 925 has the 3.89:1 ratio, four speed car.  So does 925 include four speed?  The tag from 6S1585 is an automatic car with the 3.50:1 rear axle.  Does 926 include automatic?

Your welcome - as mentioned yes the rearends identified by the 926 were installed in 66 GT350 with automatic/C4's

While we're focusing on the Feb 66 versions here is another look at examples from Jan and Feb 66. Just thought I would add that I've got records of six other cars from around your same production period at San Jose with the same tag (6BA-6BD)



As far as the "Plant Code" shown in the registry. Maybe it was meant as the code used inside the plant - code.  That plant would have been the Sterling plant where Ford assembled the completed rearends

[6s1640]

Hi Jeff again,  Thank you.

If I am reading this right, then there should be 8 more codes representing the other possible combinations of ratio options, locker or no locker.  Maybe others could help fill in the table.  I expect it is not likely a new owner would purchase a 4.11's without locker, but the possible combination exists.

Thanks

Cory

[J_Speegle]

Now remember that before (an educated guess) the first the year some applications would not have the code in that location

After that

3L89 = 924

Kevin Marti likely has a list of these since he was making them

Might have a list also that I can't think of at the moment also

[gt350hr]

  Jeff ,
     You are correct in that EVERY ratio and open or locked had it's own specific three digit ''build code". The build code sheet was a laundry list of parts and instructions on how to assemble the specific differential for consistency purposes. This was used to ID complete drum to drum axle assemblies when finished. The number was most often yellow grease pencil marked on the housing to identify the assembly instead of looking at the tag. This process continued on for many years, SP is certainly Sterling Plant. When the volume was low ( early on) and limited ratio / option wise SP was used and as production increased ( and the Detroit locker no longer being ''standard") the switch was made to the conventional numbering system. We also know "DSO" was marked on the back of early assemblies to further identify their special nature.
    Randy

[6R07mi]

Wouldn't this "axle" code be used similar to the "engine" code?
So the assembly operator would be using the build sheet that calls out the axle or engine code that is used to install the proper component??

similar process for both??

regards
jp

[J_Speegle]

Wouldn't this "axle" code be used similar to the "engine" code?
So the assembly operator would be using the build sheet that calls out the axle or engine code that is used to install the proper component??

similar process for both??

Don't have any idea how the plant communicated to the workers which rearend each line or station was assembling at the time. Never got to visit or talk to any of the workers there Guess I should have taken the tour when I had the chance - Just got the T-shirt   

[6s1640]

Now remember that before (an educated guess) the first the year some applications would not have the code in that location

After that

3L89 = 924

Kevin Marti likely has a list of these since he was making them

Might have a list also that I can't think of at the moment also

Hi Jeff,

I just spoke with Marti Auto Works.  They have a 4 to 6 month backlog on the rear axle tags.  I thought it might have been a material supplier issue, but it just a volume issue or maybe not enough employees to get these thing made.  Their website currently shows rear axle tag among other tags "Temporally Not Available".  Bummer.

Thanks

Cory

[J_Speegle]

Hi Jeff,

I just spoke with Marti Auto Works.  They have a 4 to 6 month backlog on the rear axle tags.  I thought it might have been a material supplier issue, but it just a volume issue or maybe not enough employees to get these thing made.  Their website currently shows rear axle tag among other tags "Temporally Not Available".  Bummer.

Yes they have as of now, focused they available workers to the reports and stopped doing any of the tags I understand. This started over a year ago during all the Covid. Sorry I'm not local or would offer to help out.  Hope they can get back to full or expanded strength soon since there is a demand out here that is evident from the wanted ads searching for original tags of all kinds

[6s1640]

Hi Jeff,

We may have found the transition for the "SP" being dropped and the code being added.  The below rear axle tag is from a very early full spec 66 GT350 automatic car,  post partial spec 6S252, very very late September to early October build.  Notice the absent "SP" and the "926" code.  The date code on the tag 5JD is fourth week September 1965.  This tag is the next week from the 5JC tag you posted in reply No. 3 with "SP".

Cory