Author Topic: Rally Wheel Derby Cap Differences  (Read 2055 times)

firstgenaddict

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Rally Wheel Derby Cap Differences
« on: February 02, 2013, 02:38:59 PM »
VIN 531196 69 Z28
 I noticed that 3 of my caps are different from the 4th.
They were wrapped up in old news papers with the vehicle I believe they (at least 3) were the originals. The car was run into a ditch before being parked, therefore a reasonable assumption would be the odd one is the replacement (it also has Canada inside).

The center of the 3 have a peak/point, which can be felt with the tip of your finger.
The odd one is rounded, the reflection shows the difference well however it is very easy to feel.

POINTED PEAK CAP
Note in the reflection how there is a distinct angle



POINTED CAP Reverse Markings






Rolled Bead





ROUNDED PEAK CAP
Note in the reflection how it appears as an Arc vs an Angle



ROUNDED CAP Reverse Markings





Flat Bead



SIDE by SIDE showing ROLLED BEAD vs FLAT BEAD Cap Profile

« Last Edit: February 02, 2013, 02:58:30 PM by firstgenaddict »
James
Collectin' Camaro's since "Only Rednecks drove them"
 
Check out the Black 69 RS/Z28 45k mile Survivor and the Lemans Blue 69 Z 10D frame off...
https://plus.google.com/photos/112392262205377424364/albums?banner=pwa

william

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Re: Rally Wheel Derby Cap Differences
« Reply #1 on: February 02, 2013, 08:01:00 PM »
I work in Supply Chain. All you're probably seeing there is the difference between suppliers.

When a vehicle is in production and plan requires, say, 5,000 pc/week of some trim part it is not unsual to have several suppliers. That's a decent volume and a number of suppliers would be interested in a piece of the business. Sometimes you need more than one source as seasonal demand peaks may be more than one can handle. Some companies want a source within 1 day shipping from an assembly plant. So the source for rally wheel caps for Van Nuys may have been different than the source for Norwood. Cost is a very big deal to automakers. Even during production stuff is shopped around for a better price. Suppliers can be dropped for quality or delivery issues.

Service parts are a separate consideration. Service parts have to be individually packaged and high volume suppliers many not be set up to do that. So GMPD may designate one of the suppliers to send a number of caps per week to a packager. The cap supplied may not be an exact match for the original.

When a part is no longer current MY all bets are off. Volume drops off dramatically and the suppliers that were doing 5,000/week are often not interested. They had a line set up to do your part that is no longer justifiable. So now they have to set up and run a small quantity maybe once per month. Instead of a set up charge amortized over 250,000 parts the same costs will be incurred for 500. And it has to be packaged. Not unusual to see costs triple or more when they go non-current.

firstgenaddict

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Re: Rally Wheel Derby Cap Differences
« Reply #2 on: February 02, 2013, 09:09:45 PM »
I ran an industrial manufacturing facility for 20 years, I fully understand supplier differences, and yes I had figured that the supplier changed, given that one physical mold is significantly different that the other. .
I was trying to determine when, and if any other later caps/later manufacturers had the pointed peak and also if the lines and profiles were sharper like the 3 originals.
 

FYI: The center caps on Shaugers 04C 13k mile SSRS 350 has the peaks on it...
James
Collectin' Camaro's since "Only Rednecks drove them"
 
Check out the Black 69 RS/Z28 45k mile Survivor and the Lemans Blue 69 Z 10D frame off...
https://plus.google.com/photos/112392262205377424364/albums?banner=pwa

rszmjt

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Re: Rally Wheel Derby Cap Differences
« Reply #3 on: February 03, 2013, 01:59:00 AM »
James,
FWIW, I have noticed Original Production Line Caps have the 2 ribs inside, not the single rib, also the attaching screws are different.
 I never knew about the rolled verses crimped edge, will have to have a look at my Z28 and re post.