1967 Rally hubcaps

[Ridge K.]

Re: 1967 Rally hubcaps

ridge,
No help there ,p/n 3901712 is the hub cap assembly minus the ornament. Is there a part number for the ornament ?

john

John, I'm looking at one in a box right in front of me, and the GM label is printed with the words "GR. 5.858 Cap ASM"
"ASM" is GM's abbreviation for assembly.
My vintage GM parts book is from 1974
The wording in it, under group 5.858 CAP COVER, WHEEL

is: 67 Y W/DISC BRAKES (EXC. ALUM) 3901712 CAP, GREASE (2-PIECE)
I would take "2-PIECE" to mean a complete assembly of the "hat" and the ornament, which is what is in my box, and what's been found in factory sealed GM parts boxes I've owned.

by the way, in the same parts book, part nymber 3901715 is referred to as : ORNAMENT Y/W DISC BRAKES (EXC. ALUM)

I'll include a photo of what's in the box, along with the back side photo.
I've got two complete sets of four in NOS GM boxes (as Joe frequently says, not for sale). One set is from either the late 1960s to early 1970s. One set is from the final year of service replacement availability over a parts counter. Both sets are virtually identical, however the later set has a D.O.T. approval note sticker on the GM box.
Hope this helps, Ridge.

[Ridge K.]

Re: 1967 Rally hubcaps

Ridge, My center caps have the black retainers, they appear to be painted. The 4 screws that hold the center piece of the cap have shoulders on the top with a triangle on the head of them. The bottom of the screw( bolt) looks like the taper of a small lug nut. I will not attempt to take any of the centers off. The screws( bolts) have a whiteish oxidation on them. Thank you Dale

Sounds like your's are correct, Dale (keep in mind my earlier statement that I am not a master judge. I'm not that sharp, just an old big-block guy).
I just posted a couple of pics of a NOS service replacemnt cap, along with the GM box it came in. Hope these pics are helpful. Ridge

[John D.]

Re: 1967 Rally hubcaps

I agree with Jack Humphrey's comments above about the plating. Here's why:

The drawing for part number 390175 drawn in January 66 and last revised in November 66 shows no specific gold color callout and has the following comments:

-part number 390175 must appear on the inside surface of this part.

-Chrome plate per GM 4372-M.

-Plate thickness on significant surfaces must meet minimum requirements of specifications.

-Finish must be bright on indicated surfaces equivalent to that obtained by buffing and surface must be free of imperfections.

The area that appears to be gold on known originals is not specified as a surface requiring bright finish on this drawing....so it probably wasn't buffed or held to that appearance spec during regular production in my opinion (and jacks).

material: zinc die cast alloy

hope this helps

john

[John S.]

Re: 1967 Rally hubcaps

Ridge,
I will go out and look at mine later and remove and take pics to post. Thanks for your help.
John

[Ridge K.]

Re: 1967 Rally hubcaps

I agree with Jack Humphrey's comments above about the plating. Here's why:

The drawing for part number 390175 drawn in January 66 and last revised in November 66 shows no specific gold color callout and has the following comments:

-part number 390175 must appear on the inside surface of this part.

-Chrome plate per GM 4372-M.

-Plate thickness on significant surfaces must meet minimum requirements of specifications.

-Finish must be bright on indicated surfaces equivalent to that obtained by buffing and surface must be free of imperfections.

The area that appears to be gold on known originals is not specified as a surface requiring bright finish on this drawing....so it probably wasn't buffed or held to that appearance spec during regular production in my opinion (and jacks).

material: zinc die cast alloy

hope this helps

john

John your hypothesis is not only logical, but it clearly makes sense.
But,....forgetting current day reproductions for just a moment,....how would you explain why NOS, unused examples from the same era as the center caps rubber malleted on at new car dealerships in 1967, do not show a consistant gold hue?
Were only the service replacements polished in this area, by the same OEM?
Or,... were only the service replacements triple-plated?
Just curious what your explanation would be.
I thank you in advance for your kind indulgence of me asking.
Ridge.

[John S.]

Re: 1967 Rally hubcaps

I have removed two caps with the pics below. One pic clearly shows the fading to what I believe is nickel plate. The other shows both sides. On another note, the one that has the fading also has a crack in the stainless where it bolts to the center hub. you can see it in the pic. Looks like I will be looking for some new caps. My luck, I am sure they are not cheap!

John