69 Seat Back Adjustment

[Chuck G.]

The 69 AIM shows a "fixed" bumper attached to the seat BACK with a screw and another "fixed" bumper attached to the seat BOTTOM, adjustable only by placing shims or spacers under it. Both of these bumpers, in the AIM drawings, appear approximately the same size. Here's the problem....I have a 1970 and up style threaded rod with rubber bumper in the seat BACK. I have it adjusted to my point of comfort. If I had a fixed bumper on the seat BACK, of the same approximate size as the seat bottom bumper, as the AIM shows, I would have to shim the bottom up at least 3/4 inch, and then also shim the catch assembly to correspond. I've honestly never seen an original 69 seat back adjustment assembly. Every car I look at has the 70 and up system. The NCRS Manual calls the seat BACK bumper a "stop", and the seat BOTTOM bumper a "pad". They mention the "bag of shims", found in the rear compartment. Can this be possible? Is the AIM incorrect on this item. It just doesn't seem "correct" to have to shim this amount to place the seat at the proper angle. Any help will be appreciated. Thank you. Chuck Gongloff

[Joe L.]

Re: 69 Seat Back Adjustment

Chuck----

I am somewhat familiar with the seat back adjustment "system" which you describe. I believe that early 69s might have used the seat back "stop"system described in the assembly manual which was, essentially, a carry-over from 1968. For later 69s, I believe that the fixed, upper bumper, GM #3926222, was replaced with an adjustable bolt with rubber cap, GM #3977799 or another screw/bumper combination that I am currently researching. The lower bumper, GM #3954505, remained and mated to the aforementioned part.

Early 69s came with a small, tie-string muslin bag found in the rear storage compartment. This bag contained 4, 1/4"-thick rectangular shims, GM # 3926224 and, possibly, several round shims, GM # 3926225. The rectangular shims, which were painted a metallic silver similar to the seat latch hardware, were used to shim up the seat back catch latch found on the rear of the lower seat cushion. The round shims were used to shim up the lower seat cushion bumper. Together, this was supposed to adjust the seat back angle to accomodate the needs of different drivers.

When the change was made to the adjustable upper bolt/bumper, the round spacers were omitted. My September 1969 build 69 originally came with the muslin bag with only the rectangular shims. The notion that one could effectively and satisfactorily adjust the seat back angle with these spacers was one of the greatest jokes ever concieved. I tried, off and on, for years and finally gave up.

Incidentally, the upper adjustable bolt/bumper was discontinued in 1974 and replaced with part number 400765. This part is still available today, but it is of slightly different configuration than the originals. All other parts of the seat back latch/bumper mechanism have been discontinued by GM, although I believe that Dr. Rebuild has reproductions of the bumpers available. Reproduction muslin bags with seat back rectangular shims are available from Sal Carbone's RPO Outlet.

I have a friend who is also the original owner of a 69 which he also still has. However, his car was a November, 1968 build. I'm going to check the seat latch/bumper mechanism on his when I get a chance.

[Everett Ogilvie]

Re: 69 Seat Back Adjustment

Chuck and Joe,

My 2-owner early '69 was built Oct 23, 1968. If memory serves, it uses the early shim method. But I will take another look at it (actually Dan Wilson in Farmington may have to look at it for me - we moved it up there this weekend to start restoration), and we will report back on our findings. This level of detail, on what mid year changes were made is great stuff.

Everett

[Terry M.]

Re: 69 Seat Back Adjustment

Joe, My early 1970 came with the bag and shims - of course the later style. I adjusted the seat back for "comfort" with no problems. One must allow that the definition of comfort in those days was much different than we now expect, but none-the-less crude as it was they did work.

I suspect your car missing the shims was the exception rather than the rule.

BTW thanks for your fine responses - they are consistantly great and to the point.

Terry

[Joe]

Re: 69 Seat Back Adjustment

My unrestored 4 owner '69, which was built on Oct. 9, '68 appears to have the seatback adjustment system as shown in the AIM. The seats still have the original leather covering, so I doubt anything has been changed.

Incidently, my seats do not have the chrome clip at the front, that the 68-69 Gudging Manual says were part of all '69 seats. I have seen 3 or 4 other unrestored October built '69's without this clip. Could the clip have been added at the same time the seat back adjustment system changed, or is the lack of the seatbelt clip just something else to research for the next update to the 68-69 Judging Manual?

[Everett Ogilvie]

Re: 69 Seat Back Adjustment

All, Dan W. checked out my Oct. 23, 1968 build date '69 (thanks Dan), and found: "it does have the fixed bumpers (both about the same diameter) on the right sides of the seats and the catch mechanisms on the left sides. There is not any adjustment on any of them and I cannot see any shims on any of them."

These seats also have the original, but sad, leather covers, and have not been altered. Will have to look into the chrome clips.

Everett

[Reba]

Re: 69 Seat Back Adjustment

We know that the manual is wrong about the seat clip, which was installed sometime during the '69 production. Anyone with original cars that can help pinpoint when this occurred please contact Dick Whittington, team leader for 1968-69. We are in the process of revising the manual.