Part numbers - AIM vs Parts Book

[Rick C.]

If part numbers listed in the AIM are different than those listed in the parts book, does that mean there was a change to the part between the time the AIM was published and the time the parts book was published?

For example, looking through my '62 AIM for speedometer cable part numbers I see the cable used with a 3 speed (part #1588670) is different from the cable used with 4 speed and powerglide transmissions (part #1588355). No problem with that. The sheets showing these numbers are dated June 1961. My parts book is dated less than 4 months later (Oct 1,1961) and shows different part numbers. Does this mean there were changes to the speedometer cables during those 4 months and new part numbers were issued? That doesn't seem likely. The only change I know of around that time was the color of the casing changed from black to gray. I have found other parts where numbers differ between the AIM and parts book.

Are these part number changes all due to changes in the part?

Thanks,
Rick

[Joe L.]

Re: Part numbers - AIM vs Parts Book

Rick------

There are lots of reasons why an AIM part number may be different than that shown in the P&A Catalog, even one published about the same time as the AIM. In some cases, a SERVICE part might be different than a PRODUCTION part. This is actually quite rare, but it does happen once-in-awhile.

Another reason, much more common, is that the SERVICE part and the PRODUCTION part represent a different aggregation of components. For example, the SERVICE part might include a clip whereas for PRODUCTION, there are separate part numbers for the two pieces.

Yet another reason may involve the fact that there may have been more changes in the PRODUCTION part number than are shown in the AIM. Remember, our copies of the AIM may have come from a "master" that was incomplete or not the "definitive, final edition". Also, there were up to 4 editions of the P&A Catalog printed during any given model year. While changes between editions are usually few, there are some changes. If there were not, they wouldn't have printed a new edition. Of course, for pre-1969 catalogs, it doesn't necessarily mean that any changes between editions involve any Corvette parts.

In the vast, vast majority of cases, a SERVICE part going into GMSPO inventory at the same time as the parts were being used in PRODUCTION are going to be exactly the same, and often, even if the part numbers are different. There are exceptions, of course, but they are unusual.

A change in the color of the material used for the casing of a speedometer drive cable would usually not, BY ITSELF, be a reason for a part number change. However, there could be other non-apparent changes coincident with the casing color change that could be reason for a part number change. The casing color MIGHT even be a form of a "code" to easily identify such a changed part.

[Stephen B.]

Re: Part numbers - AIM vs Parts Book

Something else to consider is that the AIM changed during the year. GM revised some pages as the year progressed. Typically, the edition we purchase today includes all of the updates by the end of the model year. I have not seen any documentation on the prior AIM pages that were revised.

[Ray G.]

Re:Did Price change = part # Change ?

Hello;

We thought(back in the day) that a part number change was often a price change.

Any validity to that theory?

Thanks, Ray

[Art A.]

Re: Part numbers - AIM vs Parts Book

"Remember, our copies of the AIM may have come from a "master" that was incomplete or not the "definitive, final edition"."
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Joe, There was only ONE MASTER for each MY vehicle line kept by the Records Retention Group at Chevrolet Engineering, aka, the File/Library/Archives. The Records Retention MASTER copy was the ONLY MASTER copy kept. It contained ALL sheets that were issued and therefore showed all the revisions that occurred and is the definitive version...................unfortunately it is NOT the version that we have available to us.

Record Retentions ALSO kept ANOTHER set of AIMs that reflected what EACH plant had on hand. This was in place so anyone at Engineering, Engineers,Specification, Drafting,Scheduling, etc, could go to RR and see what a plant was using. These AIMs were known as a LIVING document and when the Plant AIM recipients received new pages from Engineering they were REQUIRED to round file the old sheet. This is the version that we have available to us.

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"Something else to consider is that the AIM changed during the year. GM revised some pages as the year progressed. Typically, the edition we purchase today includes all of the updates by the end of the model year. I have not seen any documentation on the prior AIM pages that were revised. "
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Stephen, The LIVING version of the AIMs did NOT include all the updates at the end of the year.
The revision block on each sheet was a standardized formatted document and contained ( I don't recall the exact number and I don't have one to refer too, but I think it was around 10) lines for revisions. When revision # 11 came along, the sheet with revisions 1 thru 10 was round filed except for the MASTER copy as noted above.

If you ever saw a MASTER copy next to a LIVING copy you would better understand what I'm trying to point out.........................it is dramatic, the MASTER version is usually about three times the size of a LIVING version.

Art

[Art A.]

Re:Did Price change = part # Change ?

Hi Ray,

No, no validity, a part number change had absolutely nothing to do with pricing. That's not to say that a part number change didn't REFLECT a change in price, but it didn't drive it.

[Joe L.]

Re: Part numbers - AIM vs Parts Book

Art-----

I was not referring to the master copy in the context that you describe. I was only referring to the "master" that was used to make the printed version of the AIM's that we have today. In other words, the copy of the AIM, from whatever source it came, that was copied to make the commercially available AIM's. The fact that the "master" copy in this context differed from the definitive master copy that you describe is, essentially, the point I was trying to make.

[Joe L.]

Addendum

One more thing I should have mentioned. Sometimes a part will have BOTH a Chevrolet part number AND a part number assigned by the GM division responsible for the design and manufacture of the part. In this case, a part may, for example, use the manufacturing division part number in the AIM and the Chevrolet part number in the P&A Catalog, or vice-versa. In these cases, the part is identical but the part number is different in the different references.

I'll give you an example (although this example doesn't actually apply to the above scenario since it's a part not shown in the AIM).

The part numbers shown in the P&A Catalog for the 65-82 rear brake shields were GM #5465982, left side, and GM #5465983, right side. These are Delco-Moraine part numbers and the only numbers that these pieces were ever generally known by. However, these parts also had Chevrolet part numbers and these were GM #3864067 and 3864068. They were never orderable from GMSPO under those numbers, though.