Steering Box Finish

[Mike Z.]

In checking the archives on the subject of Steering Box Finishes, they speak almost entirely to C-2 applications. I am after several C-2 projects taking on a C-3 (1970). In reading the 70-72 JM, it indicates "Steering gear box was natural finish on earlier cars and semi-gloss black on later. 1970 often had two yellow paint inspection marks".
My questions actually could apply to C-2 or C-3. Would the "natural", actually be "as cast", which if like many other cast parts, would have a black preservative (settles primarily in the low spots and rub off the high spots) that would resist rust for a short time. If so, would the black mentioned in the JM, actually be the preservative (as cast) rather than an actual paint.
Then this leads to the question of the inspection paint daubs. I believe these would be final inspection indicators (typically yellow) just before the unit left Saginaw. I find it hard to believe, as many might, that Saginaw would do the inspecting process, then send the unit back for paint (black); therefore, the belief of the daubs under the black paint-just would not have happened, in my opinion.
My belief is the boxes were "as cast" and had varying amounts of the black preservative. Further my belief is both: C-2 & C-3 boxes would have been delivered to the assembly plant and appeared black (as cast), with inspection daubs visible. Then it would have been totally possible in the "black out" process, for black out black paint to have been over-sprayed on to the top portion of the box, which may have been sufficient to cover the inspection daubs, and therefore confirming many of the threads that black appeared primarily on the top portion.
Any thoughts are appreciated before I finish my box.
Mike Zamora
#12455

[Terry M.]

Re: Steering Box Finish

Mike,

I suppose I should remember what year Corvette you are working on now, but I don't and your public profile doesn't help me.

I believe I have a picture at home of a 1971 steering box that definitely has black paint on it, and no visible from the top inspection marks. I am not sure what else is in my photo collection or if this helps you, but allow me to suggest as politely as I can that you are over thinking this.

I don't know if Jim Shea is on vacation, but I haven't seen him post in a while. He might be able to shed some light on the question of steering box coating as well. Perhaps a private email or PM to him with a link to this thread would be rewarding.

[Jim S.]

Re: Steering Box Finish

This is a partial scan of the Corvette 1971-74 Steering Gear Assembly drawing. The drawing calls out "PAINT ASSEMBLY ALL OVER EXCEPT WHERE NOTED." The only exception called on the drawing was the pitman shaft and nut.

A question would be that the flexible coupling assembly had threaded bolts that attached to the steering column. There was not any mention that those threads needed to be protected since the car assembly plant had to install nuts and lockwashers on those bolts when they attached to the steering column flange.

Possibly the flange and coupling assembly was not assembled to the gear when it was painted. If so, then the input shaft should have been called out as a paint exception.

Very confusing. All of the gear assembly drawings from 1963 through 1982 carried the exact same paint note and the pitman shaft and nut exception.

Jim

[Wayne M.]

Re: Steering Box Finish

.... Would the "natural", actually be "as cast", which if like many other cast parts, would have a black preservative (settles primarily in the low spots and rub off the high spots) that would resist rust for a short time. If so, would the black mentioned in the JM, actually be the preservative (as cast) rather than an actual paint. ....

Mike --- FWIW, that pic of the '69+ box I showed in the thread 2 days ago "63 Steering Box" was a new service unit that came in the GM box. Checked the dating on the cardboard box inserts and shows 2/79. I don't know how that info jives with the metal tag "29_9" attached to one of the cover bolts.

But when I took the assembly out of the box, my hands were covered with what I would say was black paint. It's almost as if Saginaw oiled the unit then sprayed paint over that, but your explanation about the preservative would also explain it.

[Edward J.]

Re: Steering Box Finish

Jim, I have question maybe you can answer, I cleaned and restored my 63 box and noted there were green inspection marks on it , and did a friends 63 steering box and he had yellow marks, Do the marks mean anything, Power steering or manuel steering, As the cars one has p/strg and one manuel? Thanks Ed


Mark ,sorry for high jacking the thread.

[Michael H.]

Re: Steering Box Finish

Mike,

I'm not sure how much sense it would make to paint the steering gear black, then sit around until the paint dried before adding an inspection mark, if that's actually what it is.

From what I've seen over the decades, it appeared that the paint stripe was under the black coating, at least for 63-67.

The black coating is easily removed but the paint stripe isn't. Wouldn't that say that the black is over the stripe? If the black is that gooey, how would the paint stripe stick to it if it were on top of it.

[Mike Z.]

Re: Steering Box Finish

Thanks for the input guys, and yes Terry; I probably am over thinking this, but ain't it fun? I have a bare frame and getting all the sub-components prepared to go back on this 70, so doing a little research and questioning some of the tales and thought processes on some of these parts is interesting. I just could not understand how the inspection marks were painted over, which made my black out over-spray the only logical theory-at least from what I am seeing at this point.
Wayne-great pic of the NOS piece. It does not appear to have any inspection daubs, wonder why? The preservative I was trying to explain is what I see in your pic. It probably did not take long for it to wash off and appear that the casting was left "natural" as original cars were judged after a few years. Your pic, however kinda argues against my theory of Saginaw not painting after the assembly-otherwise the aluminum top cover would not have the paint/preservative. I always thought the preservative was applied just after coming out of the foundry, but it appears Saginaw, in this case, applied a paint process after assembly. Based on this pic, I could see the inspection daubs over this paint/preservative, or now it would make sense the inspection daubs, then the re-spray of the preservative after assembly prior to shipping.
Mike Zamora
3 1966, 1 1970, 1 1988

[Gary R.]

Re: Steering Box Finish

Mike
I've rebuild a lot of 63-82 boxes, I have seen originals that were both bare and black. My original 72 was bare iron and my 69 was black. The original 74 box I have in now was black, clear enough to see.

I have seen yellow dots,lines,and big "L" on them. The "L" I was told but don't know if true was box that leaked and was supposed to be pulled and fixed. Jim would know if this is a true statement I really don't know but I have seen that on a very few early C2 boxes. Usually the Yellow marking is on the top but this 74 had it on the radius by the large adjusting nut. The later boxes had yellow stamp letter marks instead of brush marks.

The boxes started with cast in date codes in 1974 I believe, this 74 has it and the last 73 I did I don't belive did. The metal tags on the covers started around 75 as far as I can tell from what I've seen. The service boxes also had the cover tags.

[Jim S.]

Re: Steering Box Finish

First of all, the inspection marks were never on the Saginaw engineering drawings. It was the Inspection Department's responsibility to require an inspection marking. Usually the inspection marks were added to a component when a worker performed an additional inspection to insure that something was done correctly. Since the inspection marks were not called out on the engineering drawing, the customer (the car or truck assembly plant) would have no reason or authorization to determine that the mark was on the component or not.

So if the very last operation at Saginaw (short of placing the component into a shipping tote) was to paint the component, the fact that the inspection mark was now painted over probably wasn't a concern.

However, there could be a problem area that directly affected the car or truck assembly plant. For instance, a component mounting pad came from Saginaw with a threaded hole. At times possibly the hole was not threaded properly and the assembly plant couldn't complete the attachment. This could result in real disruption at car assembly. They might get an agreement from Saginaw for additional inspection and paint marking to insure that the hole was threaded. After the process was proven to be in control at Saginaw, the marking could be eliminated by mutual agreement between the plants. Again, I don't think that the component could be rejected if the inspection marking wasn't there. Again, this was never a part of the component engineering drawing.

I could be wrong but I also don't believe you ever see any inspection markings in the AIMs.

Obviously the two letter broadcast code was for the car assembly plant. That code is shown on the product engineering drawing. So it would have had to be applied after the paint operation.

Again, I was a product engineering supervisor and not a reliability or inspection department person.
Jim

[Terry M.]

Re: Steering Box Finish

Mike,

Here is a real deal 1971 steering box. Sorry the photo doesn't show more of the box, but the box was not the intended target of the photo. IIRC this car has something like 8000 miles and has all the awards, And I do mean ALL the awards from all the Corvette judging bodies.

Jim,
You are the second guy from Saginaw to tell me about the paint on the steering box. I can not thank you enough for all you do for us. I know you are alos on other GM mark web sites and it must take up considerable of your time. Thank you for all you do.

[Ron G.]

Re: Steering Box Finish

Terry, I have to say that after looking and judging countless 70 - 72 Corvettes, I am of the opinion that it is almost a 50/50 mix of black painted and natural. My own car which I have owned for almost 38 years was natutal, but I have also owned a couple 1970's that were painted black from the factory. I personally accept them both ways. Again, some I have observed with green or yellow markings and some with nothing.

[Terry M.]

Re: Steering Box Finish

Terry, I have to say that after looking and judging countless 70 - 72 Corvettes, I am of the opinion that it is almost a 50/50 mix of black painted and natural. My own car which I have owned for almost 38 years was natutal, but I have also owned a couple 1970's that were painted black from the factory. I personally accept them both ways. Again, some I have observed with green or yellow markings and some with nothing.

I can not argue with your experience Ron. I can only point out that Jim Shea is the second Saginaw former employee to say "they were all painted." Sadly the other has passed on. I think it is clear from the drawing Jim posted that they were intended to be painted.

Oh, and my 1970 steering box (as best I remember) is painted black. Just to add another data point -- not that we need it.

[Jim S.]

Re: Steering Box Finish

Point of clarification: I use the terms "flexible coupling assembly" and "flange assembly" interchangeably.

Note: During this period of time (1965-66) there were two gear assemblies released for the C2 Corvette. The gear assemblies were only different in the style of flange assembly attached to the gear as it was shipped to St. Louis from Saginaw.

Some more confusion. The Corvette flange assembly drawing 5692974 (1965-66 with telescoping steering column) has a paint note. The 1963-66 flange assembly 5690809 used on Vettes with standard (non-adjustable) columns does not have a paint note.

The 5692974 flange assembly carries this note:
"Paint assembly with SSG Code #4239. Paint in serrations and tapped holes must not be detrimental to function or assembly of part."

Now this part does not have attaching shoulder bolts like most flexible coupling assemblies. But it has pinch bolt flanges on each side that require pinch bolts. One pinch bolt would have clamped the flange assembly to the steering gear and would have been attached at Saginaw. The other pinch bolt would have attached the steering gear and flange assembly to the steering column at the St. Louis Corvette Assembly Plant.


Now meeting the paint note spec on this flange assembly drawing could have been accomplished if the flange assembly was attached to the gear at Saginaw and then the entire gear and flange assembly painted black as the gear assembly drawing sort of indicates. So regardless as to how you interpret the Saginaw drawing(s) both the steering gear and the flange assembly for the Corvette with telescoping column should have been painted black as they left Saginaw.

However, the flange assembly used on steering gears that attach to the 1963-66 Corvettes with standard (non-adjustable) steering columns did not have a paint spec on the flange assembly drawing. (In fact, I cannot find any other Saginaw flange assembly drawings with any sort of paint note.) Even though this flange assembly has shoulder bolts and two threaded attachments, the assembly would have been bolted together before being painted as an assembly. So paint on the bolt threads would not have been relevant.

So this flange assembly might have been painted if it was already part of the steering gear assembly and that assembly "painted all over" at Saginaw before shipping to St. Louis. Or the gear was "painted all over" and the flange assembly attached to the gear after painting and then shipped to St. Louis.
Jim

[Jim S.]

Re: Steering Box Finish

I do have a service parts list for the 7806900 (1968-69) steering gear assembly. The parts list indicates that the flexible coupling, pinch bolt, and the "AM" alpha code sticker should be eliminated.

A new alpha code label "BT" added and a cardboard protector tube installed on the input shaft.

There is no mention of deleting the paint from the gear assembly.

The last gear assembly drawing that I have is 7819668 which went into production the 1975 model year through the end of C3 production. Revision "G" dated 2-12-75 eliminates Note #10 which was the "Paint All Over" note. Possibly after the paint was eliminated from this production gear it was decided to just eliminate paint on all Corvette service gear assemblies.

Jim
Jim

[Mike Z.]

Re: Steering Box Finish

Thanks again to all. Jim, you bring a wealth of knowledge and experience to the discussion and we appreciate your thoughts and opinions.
You brought up the possibility of the inspection marks we have all been talking about, may have actually been applied at the assembly plant rather than Saginaw, or even both for different reason-very interesting.
On my box; it was black, but I could not tell if black from the beginning or years of prior owners touching up the black out. The paint was similar to black out or regular paint vs. the preservative. The application was thinner of the sides and bottom, which at the time I leaned toward black out/touch up. As I cleaned it, I saw no evidence of inspection marks under the black paint. If I understand or follow your thoughts, no marks were possible, as well as marks under or on top of the preservative paint.
On my coupler: it was very evident the flanges were painted what appeared to be a semi-gloss black finish paint, not the preservative grade, which I believe follows you comments.
Based on all your input, I have a plan of attack on how I believe is the most acceptable finish process (at least to me, based on the information)-thank you.
Mike