67 Main Driveshaft Paint Dabs or "DECALS" ?

[Gary B.]

Re: 67 Main Driveshaft Paint Dabs or "DECALS" ?

That's what I thought Joe. So I guess the $69 question is how will this be judged at future events ?

Fred,

I'll take a stab at your $69 question. Based on the 30 or so C2s that I've judged chassis on, the answer to your $69 question is it will make no difference. There are a total of 5 points for originality and 5 for condition for the driveshaft and two halfshaft assemblies, including U-joints. It is so difficult to see that area of the driveshaft, that you could have paint daubs, or colored tape, or nothing at all and 9 out of 10 judges will never see what's up there and the 1 of 10 judges who can fit that far under the car to see up there I believe will never take a 1 point deduct for the paint/tape feature for either originality or condition. Even if they use a dot system for partial deducts I predict no one will ever use a dot for just that paint/tape feature.

This thread has been very interesting for its historical and academic value, but I think whatever the answer is to the paint/tape question, it will have no practical effect on judging.

Gary

[David B.]

Re: 67 Main Driveshaft Paint Dabs or "DECALS" ?

I believe the answer to your original question can be found in the Engineering print that specifically requires testing propeller shafts at 3500 RPM to verify correct Dynamic balance. In all probability the colored rings were applied during this quality control check to identify that this part met specifications. Not sure if all propeller shafts went through this testing or a percentage of production for quality control. Keep in mind this part/tube was a welded together item and was repeatedly checked for accuracy etc..

[Fred Y.]

Re: 67 Main Driveshaft Paint Dabs or "DECALS" ?

Dear Gary & David, Agreed with both. The answers also both seem to be just plain common sense. First, unless a car was being judged on a lift, most if all of us cannot see well enough underneath the car to see markings on the driveshaft, but I do believe that potentially an addendum to the JM can read that observations have been documented to show that the main driveshafts sometimes relieved a orange /green line as an inspection mark after balancing VS just the swipe of 2 brushes.

Secondly, it only makes sense that every driveshaft went through an inspection at 3500 RPM as you mentioned regardless of HP. I've seen the damage from a broken driveshaft in the drivers compartment before & it is not pretty. Potentially, say maybe every 100 shafts that were made & balanced were double checked & inspected by a "supervisor" type of inspector to make sure that quality standards were kept during the balancing of these shafts & this was specifically the "Inspectors" mark of approval.

[Patrick H.]

Re: 67 Main Driveshaft Paint Dabs or "DECALS" ?

I don't think that the stripes were brushed freehand; to me that sounds like the old "mitting" urban legend.

The edges appear to me to be build up from the tape that was used to make the edge of the stripe. Any of us can make a similar ridge by taping something, painting it, and then removing the tape.

Looking at the stripes, I don't think that the black is adhesive, as after 50 years any exposed adhesive should have dirt "permanently" attached to it, no matter how it was used or stored in the last 30. However, I can't touch it from here and see if it's sticky. Using some solvents to clean it might soften any underlying black paint (?) enough that they appear sticky, but that's just supposition.

My $0.02

[Peter M.]

Re: 67 Main Driveshaft Paint Dabs or "DECALS" ?

If anyone is interested here are some more pictures. The first is the green stripe, it looks a little like an arrow, there isn't much left. The second is the rear ujoint to pinion flange.
Kind regards

[John D.]

Re: 67 Main Driveshaft Paint Dabs or "DECALS" ?

From the part drawing......

[David B.]

Re: 67 Main Driveshaft Paint Dabs or "DECALS" ?

To further add to the color chart, there is a notation in Engineering drawing that: "shaft ass'y (HD) same as production except shot peened in area of weld also shot peened trunniun" Daub of dark green for identification. arrow pointed to rear of shaft approx --- from end.

[Fred Y.]

Re: 67 Main Driveshaft Paint Dabs or "DECALS" ?

Note to Patrick,
Patrick, the black seen on the pic is when I scratched the orange/green color with my nail. Under the color was that black which was what lead me to believe it was potentially originally a decal. If it had been painted, there would just be plain steel underneath. Either way that's really neither here nor there, I think its more the fact that that this did or does indeed exist. Thanks to Peter,John & David for those pics & blueprints.
With all this info submitted, I think I should have no issues (well I hope so) when my car goes through judging in a yr or so.

[Peter M.]

Re: 67 Main Driveshaft Paint Dabs or "DECALS" ?

Hi Fred,
You are most welcome. Have you looked at Tom Nowak's article in the newest Restorer?
Kind regards

[Fred Y.]

Re: 67 Main Driveshaft Paint Dabs or "DECALS" ?

Peter,
No, I haven't but now I'll check it out. Thanks for the heads up.

Fred

[Ralph E.]

Re: 67 Main Driveshaft Paint Dabs or "DECALS" ?

Note to Patrick,
Patrick, the black seen on the pic is when I scratched the orange/green color with my nail. Under the color was that black which was what lead me to believe it was potentially originally a decal. If it had been painted, there would just be plain steel underneath. Either way that's really neither here nor there, I think its more the fact that that this did or does indeed exist. Thanks to Peter,John & David for those pics & blueprints.
With all this info submitted, I think I should have no issues (well I hope so) when my car goes through judging in a yr or so.

Fred,
It is my understanding from a very old post by John Hinckley, which I have not yet relocated, that the manufacturer of the drive shafts for Corvettes also made the drive shafts for many other GM cars. After they were made the manufacturer would put tape markings on the shafts to mark which shafts were for which cars. Example orange and green was for corvette and place at one end. Camaro used a another color and location. The paint daubs where made at inspection points.
When I first posted about this in January I noted the markings on my car looked like tape and I still believe they are tape. FYI my car is a very early car, first week of production.
It is my opinion the markings are tape. The reason the makings last is because they are protected by the cars frame.

[Fred Y.]

Re: 67 Main Driveshaft Paint Dabs or "DECALS" ?

Ralph, that sure makes alot of sense. Id love to see the article you mentioned. And YES those marks weather we decide to call them stencils or tape (which in my gut ,I still think they look most like) were /are directly above the frame crossmember & greatly protected from the elements. I saw no other inspection marks on the main shaft, however I did see the typical remnants of the green paint inspection swipes on the 1/2 shafts. I'll have to go back through my pictures & look. Either way, the marks on my main shaft extend all the way around & I plan to keep them where they are. Let us know if you come across that article. Thanks,Fred

[Perry M.]

Re: 67 Main Driveshaft Paint Dabs or "DECALS" ?

I am trying to follow this thread but can only get to #27. There are 41 threads but I can't find them. I'm at the bottom of what I believe is the first page but there is no button to click on to get to the remaining threads. Am I the only one that can't figure this out?

[Peter M.]

Re: 67 Main Driveshaft Paint Dabs or "DECALS" ?

Hi Perry,
When you open the thread you should see "Hybrid view", if you scroll down to the bottom you will see "more replies below current depth" click on that and you should be good.
I am not computer literate so I can't explain why the program does what it does but it is VERY frustrating.
Kind regards

[Perry M.]

Re: 67 Main Driveshaft Paint Dabs or "DECALS" ?

Thanks Peter. I did that a few times but it didn't work for me then but now it does. I also note that my post has been given a #1 post and your reply was given a #2. I don't get it but that's alright. Thanks again.