Author Topic: Driveshaft yoke & C6 yoke markings  (Read 3093 times)

Offline mungus

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Driveshaft yoke & C6 yoke markings
« on: May 12, 2018, 02:15:26 AM »
In the process of detailing the driveshaft for my March 68' Metuchen GT 390 FB.  8)

The shaft appears OEM, lightly rusted bare steel with 3 x 1" wide color bands; Red - Blue - White (front to back), and also the remains of another ring near the front, no clear color, but my guess is a very faded white or light yellow, and maybe 3/4” thick. Couple of patches of underbody sealer here and there.

The yokes had what looks like faded primer red on parts of them, and the slip yoke on the C6 has what seems like pink?

With so much loss of paint etc and variations seen from web searches I am wondering how to re-finish the yokes?
Paint both of the driveshaft yokes primer red and the C6's slip yoke pink?

The Dead Nuts On driveshafts have no yoke paint that I could see, but others have them an orange color.
So far I haven't found any other C6 slip yokes that have any OEM daubs on them.

Any advice? 
« Last Edit: May 12, 2018, 07:30:36 AM by mungus »
March 14th 1968 - Metuchen S code Fastback
C6 auto, LS 3.25 diff, Gulfstream Aqua, Black Vinyl, Headrests, Console, GT group, PS, PB, AM/FM stereo, F70 tires, tinted glass, louvered hood.

Offline J_Speegle

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Re: Driveshaft yoke & C6 yoke markings
« Reply #1 on: May 12, 2018, 07:00:24 PM »
Looking at build sheets for similar cars (don't have any specifically for 68 390 4V auto) that likely used the same driveline I offer the following for consideration.

1- Do have  on photo of a 68 390 4V automatic driveline with markings and visually they look the same as far as stripes

2- Pictures and buildsheets for these other applications (specifically 68 KR or CJ automatic)  all appear to have the same color stripes for identification. One difference is that they are listed as (in reverse order when listed on the buildsheet) as light blue, dark blue and red. 

3- Since we're dealing with digit pictures and the colors can be off would at least offer that in some the "white" looks to be bluish and might show a truer blue if cleaned off more and the top layer stripped away




Driveline yoke ends were painted for identification purposes and before they were installed/welded to the driveline tube so the paint would be burnt in areas near the welding as shown in the driveline restoration article posted in the Library. On the same drivelines mentioned above in pictures the ends have the remains of orange on some of them.




Do have automatic C6 trans yokes with which are a bit brighter than the color you posted. They are somewhere between Fuchsia and the Pink posted in the color chart part of the Paint Mark article in the Library


Hope this helps
Jeff Speegle

Anything worth doing is worth doing concours ;)

Offline mungus

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Re: Driveshaft yoke & C6 yoke markings
« Reply #2 on: May 12, 2018, 07:43:12 PM »
Thanks very much Jeff, that solves the mystery around the shaft yokes and C6 yoke too.

My "white" stripe is definitely white, the iPhone photo actually came out pretty true to life this time. I did use some cutting paste on one bit to see what the color was like, sharing your view on fading etc,  and its just the same, only brighter. :-)

BTW this is a 3" driveshaft vs. the 3-1/2" ones, (if that makes any difference), and I have seen another unmolested 3" 1968' 390/C6 shaft with the same 3 stripes as mine. I noted that the "Dead Nuts On" 390 driveshafts also use this combination in their webshop picture (attached), so perhaps its correct?  Although I note that suspiciously both their 4 speed and C6 shafts use the same webshop photo... They do however, also say that striping arrangement is used for 1967 (see their graphic attached). Do I see a pattern developing? Was 67-69 the same for color codes using the 390/C6, I guess that makes sense?

The other photo, (old shaft by new) also shows that, albeit with the end yellow rings added. I have heard several versions of what these extra 2 stripes mean, most commonly that the 3 colors grouped together are for engine & trans, and that the others are for misc. plant specific purposes on the assembly line. Still all I have in that respect is a less rusty ring with no paint remaining, on one end. A bit hard to say with any certainty what it was... :-(

I wonder too, was their variety amongst the plants? I did read somewhere that the shafts were all done by Ford (in Dearborn) then shipped out to NJ, SJ or wherever, is that true? In which case they should be the same for all 390/C6 assemblies??? Do they vary between 2V and 4V? It is I think its fair to say, that this is an unmolested 390/C6 Mustang driveshaft, but thats all I could concretely say. But if its not what came with my 4V 390 / C6 car, I can at least do my best to get it right now.

Anyway that's a big help Jeff, as I can at least do the yokes now. Although one last thing on that part. Were the yokes completely painted orange / pink or was it just a brushed on portion or them? Mine have no paint near the UJ bearing holes, but then that could have been knocked off... The C6 yoke seems to just have a big daub of pink, not a complete covering.

Thanks again.
« Last Edit: May 12, 2018, 07:49:00 PM by mungus »
March 14th 1968 - Metuchen S code Fastback
C6 auto, LS 3.25 diff, Gulfstream Aqua, Black Vinyl, Headrests, Console, GT group, PS, PB, AM/FM stereo, F70 tires, tinted glass, louvered hood.

Offline J_Speegle

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Re: Driveshaft yoke & C6 yoke markings
« Reply #3 on: May 12, 2018, 08:50:44 PM »
............. Was 67-69 the same for color codes using the 390/C6, I guess that makes sense?

Not what I've seen, have records of or buildsheets support at this time IMHO. Would be careful mixing and comparing details outside of the time frame your focusing on since there is history of color stripes changing two or more times for the same application in the same production year. I would disregard anything related to any other year.

Hope Jack doesn't mind you taking his pictures (hope you asked) but I don't see a relationship between those markings and yours. IMHO I would just stick with what you have

Though it does not directly relate to you spring built car earlier big block automatic equipped 68 Mustangs and Shelbys also carried the same Light blue, Dark Blue, Red markings according to factory documents. Likely a group of 60 cars or so. Just got another stack of 68 buildsheets - haven't gone through those let but expect they will be identical in this area and the others I have

Could the driveline provider messed up on yours or a small group of the same drivelines? Maybe but it would have likely created problems in the line when the worker read the sheet and went looking for the matching driveline. Guess it could have been caught early and all the mismarked ones placed in the bin thatg normally held that application's (BB with automatic) driveline and the worker choose from that bin since he always took from that bin for that application. Basically a work around



I wonder too, was their variety amongst the plants? I did read somewhere that the shafts were all done by Ford (in Dearborn) then shipped out to NJ, SJ or wherever, is that true?

The marks at least the identification ones are clearly the same at all three plants if you stay with the same application and time period. This can be documented by the buildsheets.  The ID markings were applied at the supplier not at the assembly plants. Not sure who the supplier was or if there were multiple suppliers. Have only run across one worker that had anything to do with the production of the drivelines over the years and that was through a good friend




One word of warning and that is likely too strong of a term, about reading allot of stuff that has been placed on the web since it became available to the public . Just a word of caution as always
« Last Edit: May 12, 2018, 08:58:19 PM by J_Speegle »
Jeff Speegle

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Offline mungus

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Re: Driveshaft yoke & C6 yoke markings
« Reply #4 on: May 12, 2018, 10:02:34 PM »
All good advice. Yes I always take what individual bits of evidence I find on the web with a grain or salt. I just grab every bit of evidence I can find then sift through to find a consensus, if there is one. This place is where I get the answers I trust most.

As I cant say for sure that my driveshaft is the actual one fitted to my car in March 68' in Metuchen, so I'm thinking your "Light blue, Dark Blue, Red markings" might be the way to go. I know my C6 was rebuilt at some stage, so the shaft must  have come out at some time or other.

I must admit I didn't give much thought to ownership on those couple of photos. Perhaps reticient of me.  I have bought a couple of things from Jack (lovely new alternator etc) and know he's always keen to find correct driveshaft colors (says so on his website, even offering discounts to those who can provide such info in certain cases), so I guessed as this is all adding to the body of knowledge, that he wouldnt mind? Will keep it in mind in the future.

As an aside I found that the yoke orange shown in the library is a dead match for some FIAT tractor orange (pre 1982) that I had in my barn!
Loved the driveshaft restoration article you had in there BTW, im thinking I'll do the same. Already sanded down to 400, and as a gun owner I have some bluing liquid.
March 14th 1968 - Metuchen S code Fastback
C6 auto, LS 3.25 diff, Gulfstream Aqua, Black Vinyl, Headrests, Console, GT group, PS, PB, AM/FM stereo, F70 tires, tinted glass, louvered hood.

Offline J_Speegle

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Re: Driveshaft yoke & C6 yoke markings
« Reply #5 on: May 12, 2018, 10:26:48 PM »
All good advice. Yes I always take what individual bits of evidence I find on the web with a grain or salt. I just grab every bit of evidence I can find then sift through to find a consensus, if there is one. This place is where I get the answers I trust most.

As I cant say for sure that my driveshaft is the actual one fitted to my car in March 68' in Metuchen, so I'm thinking your "Light blue, Dark Blue, Red markings" might be the way to go. I know my C6 was rebuilt at some stage, so the shaft must  have come out at some time or other.

Its  your call since you have way more knowledge about what you've been finding and documenting about the car> Original eng, trans and rearend might lead you to the possibility that the driveline is the original as is the yoke. In that case after careful documentation I would go with what you found but remind others that see it and that might copy of the facts as you know them so it doesn't get copied.

Are the front U joints (attaching the yoke and the driveline) original?  Yoke already matches others and it the U joint is original - then more points supporting keeping and reproducing what you found


Now if allot of signs lead you to believe it is not original then go with the data that has been documented

I find that there are allot of people taking the easy route, borrowing here and there details rather then spending the time, like you, looking for specific answers to specific needs. Just copying and falling "in line" when there is evidence to the contray produces allot of cookie cutter looking finished cars. Not what these cars looked like originally. It's a fine line to follow and is full of choices at every turn.

No one said this would be easy... and if it was everyone would be doing it ;)
Jeff Speegle

Anything worth doing is worth doing concours ;)

Offline Coralsnake

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Re: Driveshaft yoke & C6 yoke markings
« Reply #6 on: May 13, 2018, 11:57:02 AM »
What you found is the best reference. I wouldnt copy something else.

Typically, yoke end were orange and not 100% coverage. The pink on the slip yoke is the same, not 100% coverage...just an ID.

The light blue, dk blue, red driveshaft was also used on NJ built 428 Cobra Jet cars and 428 PI cars with automatic transmissions. So, I suspect it is the big block driveshaft for all auto trans cars.
« Last Edit: May 13, 2018, 12:01:17 PM by Coralsnake »

Offline mungus

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Re: Driveshaft yoke & C6 yoke markings
« Reply #7 on: May 13, 2018, 06:48:00 PM »
Thanks for the coverage comments, that issue was still in my mind.

A friend had an X code with the same driveshaft markings as mine, so perhaps mine was swapped at some stage?
Did note your websites section on Metuchen big block driveshafts, and had the same thoughts.
Perhaps then the red and mid blue colour denotes FE big block / C6 and the white or light blue stripe refers to 2V or 4V?

Anyway I’ve got some things to go on now.
March 14th 1968 - Metuchen S code Fastback
C6 auto, LS 3.25 diff, Gulfstream Aqua, Black Vinyl, Headrests, Console, GT group, PS, PB, AM/FM stereo, F70 tires, tinted glass, louvered hood.

Offline Coralsnake

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Re: Driveshaft yoke & C6 yoke markings
« Reply #8 on: May 13, 2018, 07:05:30 PM »
I think its going to be all big, block automatics... the all show p. no. C8ZZ-4602-C in the MPC. The is reference to some 390s using a different driveshaft that is slight longer than the one you showed in this post, but it is a 3 inch diameter.  The only other 1968 big block driveshaft is for 4 speeds.

...that would include the 390s (including X-codes), 428PI and 428 CJ. I seriously doubt each of the colors have individual meanings.

I think its unlikely some swapped out the driveshaft with the one you showed above, unless you know your car does not have the right drivetrain. Listen to your car.
« Last Edit: May 13, 2018, 07:07:47 PM by Coralsnake »

Offline mungus

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Re: Driveshaft yoke & C6 yoke markings
« Reply #9 on: May 16, 2018, 01:23:07 AM »
Ummm did I miss something or did a few pages of "spirited" discussion disappear from this thread?

Just wondering as I think I looked at some MPC pages, and 68' FE driveline PN exerts that are now MIA.
I did have a Q on them as it seems one source showed a C7ZZ PN and the other dox showed a C8ZZ PN...
Anyway not to worry, seems we have an idea of what to do.

Thanks everyone for the input.

 :D
March 14th 1968 - Metuchen S code Fastback
C6 auto, LS 3.25 diff, Gulfstream Aqua, Black Vinyl, Headrests, Console, GT group, PS, PB, AM/FM stereo, F70 tires, tinted glass, louvered hood.

Offline J_Speegle

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Re: Driveshaft yoke & C6 yoke markings
« Reply #10 on: May 16, 2018, 01:28:58 AM »
Ummm did I miss something or did a few pages of "spirited" discussion disappear from this thread?


Should have come up as a new post when you visited the site again. Got a bit off of the OP focus on paint markings for a specific application so just split to make it easier for others to find and follow in the future and with the search feature

68 Driveline Discussion - Split from another thread

http://www.concoursmustang.com/forum/index.php?topic=18165.0
Jeff Speegle

Anything worth doing is worth doing concours ;)

Offline mungus

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Re: Driveshaft yoke & C6 yoke markings
« Reply #11 on: May 16, 2018, 01:36:02 AM »
Thanks Jeff.
March 14th 1968 - Metuchen S code Fastback
C6 auto, LS 3.25 diff, Gulfstream Aqua, Black Vinyl, Headrests, Console, GT group, PS, PB, AM/FM stereo, F70 tires, tinted glass, louvered hood.

Offline mungus

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Re: Driveshaft yoke & C6 yoke markings
« Reply #12 on: May 16, 2018, 04:24:17 AM »
Progressing well however I have one last thing; My mystery missing front ring's color.
This was centred 6-1/2" from the end of the shaft's tube, where it meets the front UJ flange. And it was 1/2" thick.

This was just an empty ring when I got the shaft, no color visible. So I'm guessing its some kind of plant specific assembly coding?

Any memories about what one typically sees with a Metuchen 68'  S code / C6 front driveshaft ring?
Most shafts seem to have a white or yellow ring there. (Its white on the D.N.O. offering).

As the shadow of the ring is still there in the steel (never rusted), I feel its best I paint it.
March 14th 1968 - Metuchen S code Fastback
C6 auto, LS 3.25 diff, Gulfstream Aqua, Black Vinyl, Headrests, Console, GT group, PS, PB, AM/FM stereo, F70 tires, tinted glass, louvered hood.

Offline J_Speegle

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Re: Driveshaft yoke & C6 yoke markings
« Reply #13 on: May 16, 2018, 06:03:39 AM »
Progressing well however I have one last thing; My mystery missing front ring's color.
This was centred 6-1/2" from the end of the shaft's tube, where it meets the front UJ flange. And it was 1/2" thick.

This was just an empty ring when I got the shaft, no color visible. So I'm guessing its some kind of plant specific assembly coding?


Don't believe so. Its just not part of the identification coloring but had some other purpose

Any memories about what one typically sees with a Metuchen 68'  S code / C6 front driveshaft ring?
Most shafts seem to have a white or yellow ring there. (Its white on the D.N.O. offering).

Well since those are not the same as yours I would not copy them.  Would run short one stripe before I guessed at the color but just me since you have a greater chance of being wrong than being right.

As the shadow of the ring is still there in the steel (never rusted), I feel its best I paint it.

If you restored the driveline that metal should all be smooth and you will not see any evidence of past stripes - one of the reasons for documenting everything before you start the process ;)
Jeff Speegle

Anything worth doing is worth doing concours ;)

Offline mungus

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Re: Driveshaft yoke & C6 yoke markings
« Reply #14 on: May 16, 2018, 07:06:59 AM »
Fair enough. I won’t paint that stripe. If I get more information later on I’ll do it.
March 14th 1968 - Metuchen S code Fastback
C6 auto, LS 3.25 diff, Gulfstream Aqua, Black Vinyl, Headrests, Console, GT group, PS, PB, AM/FM stereo, F70 tires, tinted glass, louvered hood.