69 front spindle inspection marks

[Greg L.]

I just came across these pics and thought some would like to see them.

The one on the left show what remains of an orange inspection mark. They also show that the spindle to knuckle hardware was zinc or cad plated.

The one on the right also shows what remains of an orange inspection mark.

This last one I'm a little confused about.... The right one shows what is left of the blue/green inspection mark but the left one seems to have what remains of a orange inspection mark. Since both spindles are the same it can't be to determine a left and right spindle. Is it possible to have orange inspection mark on one side and a blue/green one on the other side. Not a big deal...just curious.

Greg Linton
#45455

[Jim V.]

65 front spindle inspection marks

Who knows????...Both have white marks at bottom ball joint.


While driver's has green and passenger has white dabs just above spindles

[Chuck S.]

Re: 69 front spindle inspection marks

"...Since both spindles are the same it can't be to determine a left and right spindle. Is it possible to have orange inspection mark on one side and a blue/green one on the other side?..."

I found similar orange markings on BOTH sides on my late 70, but there are other marks that were different side to side. On the upper part of the spindle, there was a wide lavender stripe on the right? side, and on the bottom inside on the left spindle there was an olive green daub. There was also white paint marks at the top ball joint on both sides, and white lumber crayon marks across the bottoms on both sides.

My printer is supposed to scan...I'll see if I can post some pictures.

[Chuck S.]

Re: 69 front spindle inspection marks *NM*

[Chuck S.]

Re: 69 front spindle inspection marks *NM*

[Chuck S.]

Re: 69 front spindle inspection marks *NM*

[Chuck S.]

Re: 69 front spindle inspection marks *NM*

[Joe L.]

Re: 69 front spindle inspection marks

Greg-----

I believe that the reason that different inspection marks is seen on these spindles is that few, if any, of the marks were emplaced on the spindles from their manufacturing source. Instead, the marks/paint daubs were applied to the spindles as part of the assembly process which built up the complete front spindle assemblies as delieverd to St. Louis.

[Greg L.]

Re: 69 front spindle inspection marks

Well that's all quite interesting and it seems that as Joe says, the marks only mattered on the assy line. Maybe the fact that any mark is there rather than a specific color is there was all that mattered depending on the phase of assembly... Who knows.

In aviation we use a product called "torque seal". It is a paste in a very small tube that is applied as a thin stripe across say a nut and bolt or bolt head and the surface that it is holding. The idea is that if the nut or bolt comes loose, the seal will be disturbed and easy to spot during routine inspection. I have a pink tube in my box that I use....some have yellow and others green and it makes no difference what color is used just as long as something is used. Sounds somewhat like suspension markings to me...

Neat pics guys...I'll have to file those for future reference.

[Chuck S.]

Re: 69 front spindle inspection marks

..."It is a paste in a very small tube that is applied as a thin stripe across say a nut and bolt or bolt head and the surface that it is holding. The idea is that if the nut or bolt comes loose, the seal will be disturbed and easy to spot during routine inspection..."

Sorry, Greg, but I'm skeptical of your theory.

Even today, automobiles are not subjected to the same exhaustive regular inspections as aircraft. In spite of more government attention to automotive saftey, new cars have even fewer inspection marks than the old cars. State safety inspections are generally limited to checking to see if the vehicle has good brakes, functioning lights, turn signals, wipers and horn, and has a tight exhaust system. In my opinion, no effort is made to verify chassis fasteners for several reasons...time, liability, and a plethora of different types of chassis.

The coverage of the paint marks on the old cars is incomplete...some cars have few marks, some (like my spindles) are loaded with them. More or less marks may have had more to with impending shift changes. In my opinion, the paint marks were not a "safety seal"...If they were a "safety seal", then EVERY car would have to have the same marks. In my opinion, the marks were there to remind the inspector himself, and all other inspectors, supervisors, and line workers that he had checked those fasteners and found them to be satisfactorily torqued. Once the car was out the plant door, they served no further purpose.

The only time a mechanic would have ever seen one of these inspection paint marks broken is when the car has been towed in with a collapsed front end, or the customer is complaining that his front end is shaking like heck...he wouldn't need to see the paint broken to figure out the fasteners are gone or loosened.

Another reason I don't believe the marks were a "safety seal" is that I found white crayon inspection marks on my steering linkage that didn't cross any fastener or thread...they are simply drawn around the drag link end and down the bar to the other end.

I have seen paint applied as a "safety seal" in automotive applications, but it is usually on sensitive instrumentation or electronics where the manufacturer wants to know if someone has opened or tampered with the component. I first saw these "safety seals" on import vehicle components like the inlet air meter, anti-lock brake units, and the ECM. These safety seals were white and yellow paint, applied as very small and inconspicous spots on fasteners or a cover edge.

[Greg L.]

Re: 69 front spindle inspection marks

Actually I totaly agree with you Chuck in that the paint marks were not used as a safety seal like in aviation.

What I was trying to say is that we use this torque seal for the same purpose regardless of the color...it does the same job whether it is blue, red, yellow or what ever.

I'm thinking that the paint marks on our Corvette were used in the same way with no real regard for color. Say for example once the lower balljoint stud hole in the spindle was finished being machined and checked it would get a daub of orange paint so that the machinist, assembler or whom ever would know that that part of the manufacturing process was done. Now say there is a shift change, end of a production run, run out of orange paint or what ever and all of a sudden a different color shows up on the same area...say now it is a blue/green instead of orange. To the machinists or inspectors it still might mean the same thing even though it's a different color.

Does that make sense or am I off my rocker?

[Chuck S.]

Re: 69 front spindle inspection marks

Oh, I see...I mis-interpreted your comments.

Yes, I agree...the apparent different use of the orange on our two spindle sets makes me believe the paint color is more likely to have been tied to a given individual than the function being performed.

On my spindles, the orange paint is clearly targeted for the single large 9/16" bolt on the upper part of the spindle; on yours, the orange paint is targeted elsewhere, and then only on one spindle...perhaps the shift change occurred between the time the one spindle was inspected, and the other side was inspected

In my opinion, the orange paint was a specific inspector's "signature" that he had performed the function and found it properly completed. Different paint colors for the same respective fastener on the two sides probably means the inspection process was picked up and completed by another inspector...JMHO.

[John H.]

Re: 69 front spindle inspection marks

You seldom see "inspection marks" on critical engine or chassis fasteners these days on modern cars, as few air tools are used on them any more. Virtually all critical fasteners are driven using computer-controlled DC electric nutrunners whose transducers upload the precise torque and angle of every fastener to that car's electronic production record in the plant's Factory Information System, which flags any issues instantly on the operator's display screen (in addition to a green "OK" light or flashing red "Not OK" light on the tool itself).

All the overhead-hung gray boxes you see in the photo are the interface controllers for each of the electric DC nutrunners in use in the area; some also include nests for multiple socket sizes used on the same electric tool - when a given size socket is removed from its sensor-equipped receptacle, that automatically reprograms the interface box with torque/angle parameters unique to that size fastener so an operator can use one tool for multiple different-size fasteners. With this technology, there's no question about whether critical fasteners were properly torqued, and it's electronically recorded for every fastener.

[Chuck S.]

Re: 69 front spindle inspection marks

Thanks for interesting insight into the modern process, John...I thought the lack of inspection marks was probably related to better assembly tools and strict quality control discipline on torque calibration.

It sounds like the tools have the capacity to continuously self-calibrate. Recording of torque values on the plant data system was something I was told on the Bowling Green tour, but I had forgotten that fact.