1976 Rolling Model Change

[Jim S.]

I did some research for a question on the CF with respect to Rolling Model Changes (RMCs) made during the 1976 Corvette model year.

The 1976 Vette model year had many RMCs that are documented in my two 3 inch 1976 AIM binders. I ordered and purchased a new 1976 Vette. One of the earlier changes was to the rubber rear bumper cover. One RMC that I know occurred was a change to the CORVETTE rear name plate and bumper cover. The 1976 start of production plate was small and fit into a relief molded into the cover. The CORVETTE name plate was made larger and the cover was modified to be flat. My Vette arrived at the dealer in early May and the name plate was the larger one. This change was not documented in my AIM books. It only shows the later large script name plate and completely flat rear cover.


FYI, my Vette came with he "old style" A6 air conditioning compressor.


I did see a very late 1976 Vette and it had an overhead dome light (not in the rear view mirror).


I was able to obtain a two volume set of 1976 Corvette AIM manuals directly from Chevrolet Engineering. Whether they were up to date or the latest info, I do not know. They did have many sheets labeled as "Rolling Model Change."
I do not know if AIM books available from other sources have this 'Rolling Model Change" info or not.

These are the various build catagories with "Rolling Model Change" on the various AIM sheets:

Storage compartment behind the seats.
Windshield moldings
Sun visors
R4 AC compressor
AC lines
Roof panels and Roof panel locks
Coat hook
Rear window trim panel
Roof panel stowage strap
Horns
Underhood wiring for the R4 compressor
Dome light
Elimination of the rear compartment lamp
Radiator mounting and support seals
Radiator fan shroud
Rear bumper bar
Tail lamp mounting panel


Several sheets have "Waiting Layout Approval" on them. I do not know if that tied into Rolling Model Changes or not.

Rolling Model Changes were supposed to save General Motors considerable money. By "Pulling Ahead" changes instead of making them a model year change was supposed to reduce obsolesence because the assembly plant was supposed to work the new parts into the system as old parts ran out. I doubt that it really worked that well however.

Jim

[Bryan S.]

Re: 1976 Rolling Model Change

This is a great thread and should be of assistance when the judging manual is revised. The 1976 model year had many rolling changes as you indicate. Perhaps you can contact the judging manual revision team and send them your information.

[Jim S.]

Re: 1976 Rolling Model Change

As I mentioned. I don't know if my two volumes are unique or are the AIMs currently available the same? I could loan my AIM books to NCRS persons if I knew who to contact. I also borrowed the 1975 AIM books from Engineering. I did not copy every sheet but I compared the 1975 to the 1976 AIM and copied every 1975 page that was different. So I do have a mixture of 1975 with 1976. In hindsight it would have been much better to have copied the 1975 manual complete.

Jim

[Patrick H.]

Re: 1976 Rolling Model Change

Interesting. I did some moderately extensive work on a 1976 this fall, and was noting how many early/late parts and changes there were in the model year. I believe that the car was a May built car, yet still had many "early" features. Since I was redoing the AC system, it was especially those items that I noted were early, but also the radiator seals, mounting, shroud, etc. It took some extra diligence to find the matching parts and order the right ones.

Patrick

[Steven B.]

Re: 1976 Rolling Model Change

As I mentioned. I don't know if my two volumes are unique or are the AIMs currently available the same? I could loan my AIM books to NCRS persons if I knew who to contact. I also borrowed the 1975 AIM books from Engineering. I did not copy every sheet but I compared the 1975 to the 1976 AIM and copied every 1975 page that was different. So I do have a mixture of 1975 with 1976. In hindsight it would have been much better to have copied the 1975 manual complete.

Jim

Jim, at the top of the page is CONTACTS. Select CONTACTS and you will fine Brian Pearce and his email address. Steve

[John H.]

Re: 1976 Rolling Model Change

It wasn't at St. Louis, but I remember the "Rolling Model Change" well - I planned and executed the first GM high-volume Rolling Model Change on the 1974-to-1975 Vega at Lordstown at 103 per hour when I was the Trim-Chassis-Final Production Superintendent, and it came off quite nicely. Among other things, we left one empty carrier between the last '74 and the first '75, and printed the Body and Chassis Broadcast copies on pink paper for the first ten 75's. The amount of detailed advance planning for material storage and display and cooperation between Material, Production Control, Industrial Engineering, and Specifications Departments was FAR more than anticipated.

[Tom B.]

Re: 1976 Rolling Model Change

I am the original owner of a 76 Ordered on Feb 12 76 Aluminum wheels and L82 were on constraint I received my car May 29 76. It has the earlier features A6 compressor Rear compt coutresy lite. I believe late in 76 production on the window sticker power steering and brakes were standard and there was a price change on sticker. I also believe in very late 76 Leather int became standard like it was in 77 there were no vinyl interiors in 77.

[Jim S.]

Re: 1976 Rolling Model Change

Now that you mention aluminum rims.

If I remember correctly, all four rims had to be replaced because of air leakage do to porosity in the castings. Also, I received five new Firestone 721 radial tires to replace the Firestone 500 radials.
Jim

[Don G.]

Re: 1976 Rolling Model Change

A Rolling Model Change was utilized on those GM models that did not have a major design change but was essentially a "carry-over" design. The objective was to have the first new model follow the last old model eliminating the traditional line stripping and reduced line speed at the start of the new model. As John Hinckley noted, this required a great deal of logistics coordination and assembly line employee training because even a "carry-over" model could have 500-1000 new part numbers replacing old part numbers. To reduce the number of part numbers changing on "the day of the roll", the Material Control Department would request as many parts as possible be either brought in early and use them on the old model or use the old model parts for a brief period on the new model. This was called "pull ahead or lag along". Engineering only approved these requests that met three criteria:
1. had no negative impact on emissions or fuel economy
2. did not affect the appearance of the vehicle from the customer's perspective
3. the old and new part must be interchangeable with mating parts of the old and new models.
This was an accepted GM practice and needs to be a consideration in the judging process.

[Jim S.]

Re: 1976 Rolling Model Change

eMail sent to Brian.
Jim

[Walter G.]

Re: 1976 Rolling Model Change

I ordered/owned a new '76 as well. Mine was delivered on March 17th and had the smaller emblem on the rear fascia. I recall looking at a red/red example at a local dealer that had the standard vinyl seats. They were vertical pleats vs the horizontal orientation of the optional leather covers. Not too many of the standard ones were produced/sold, I would imagine, and I haven't seen one in years. When worn out most owners probably replaced them with leather. Kind of like finding a '68/'69 with an original 3-speed manual today. I also had the Firestone 500's replaced under warranty and settled for rally wheels due to constraints on the aluminum ones when I placed my order.

[Art B.]

Re: 1976 Rolling Model Change

Hi Jim. Karen and I purchased our 1976 new with 7 miles on it from Ed Rinke Chevrolet in Detroit in September of 1976. It was one of two late production cars that were still on his lot this late in the model year. It now has 23,000 miles on it and almost all of the parts on the vehicle are original except for filters, battery, tires (replaced by Firestone during the 500 recall), and the mufflers which finally rusted through last year en route to an NCRS event. Everything else including belts and hoses are original. It received top flight at the Novi national in 2008 but did not get Bow Tie due to some body damage repair that was discovered that must have occured prior to delivery. If you have any questions about a late production car I would be more than happy to share either pictures or a description of any specific area. I am looking forward to any additional information you share with us regarding the rolling changes.

[Tom B.]

Re: 1976 Rolling Model Change

Art....what serial number sequence? Mine is in 35000 range Have the older components with a May build. Mine has 9K miles all original.

[Jim S.]

Re: 1976 Rolling Model Change

FYI, my '76 was delivered on April 22, 1976 and was in the 31000 range.
I know this is not about 1976 Vettes but digging through my archives I find the following info on 1975 Vette production figures. I got these directly from Chevrolet.

Full Model Year 1975 Corvette production 38465
Model Year to End of Month Date

Oct 74 02385
Nov 06180
Dec 09190
Jan 75 13159
Feb 17112
March 20856
April 25228
May 29379
June (approx) 33922
July 38465

[Jim S.]

Re: 1976 Rolling Model Change

Just in case you didn't notice that I had added this 1975 model year info to the above posting.

I know this is not about 1976 Vettes but digging through my archives I find the following info on 1975 Vette production figures. I got these directly from Chevrolet.

Full Model Year 1975 Corvette production 38465
Model Year to End of Month Date

Oct 74 02385
Nov 06180
Dec 09190
Jan 75 13159
Feb 17112
March 20856
April 25228
May 29379
June (approx) 33922
July 38465