Glovebox Revelations

[Tomnistuff]

As I was preparing to reassemble my late 230SL glovebox for reinstallation, I started discovering things that stimulated the “Why did someone do that?” part of my brain?  

To wit:

1.   Why are my two rivets missing?  You know - the ones that are supposed to hold the door/hinge/glovebox together to aid installation?

2.   Why, in the 27 years since I have owned my car, has the glovebox always been installed with six lower and two upper screws instead of the four lower and two upper screws that everyone says should be used to install it, and that all the “restored” cars appear to have?

So I hauled out my Big Blue Book and paged to the back (Job No. 68-1, Removal and Installation of Glove Compartment – 230SL), and had the shock of my life (well, perhaps that is a bit of an exaggeration).  Anyway, something seemed very, very wrong.

I read the disassembly and reassembly instructions several times very slowly and used a jeweler’s loop (2 ½ X) on the photos, then said to myself, “I’m going to have to think about this before posting my discovery on the Pagoda forum.  This is going to upset some people, unless I’ve missed something.”  

I hope that I’ve discovered something that everyone but me knew already and just forgot to mention, but I suspect that those who already know what I found in the BBB can be counted in the single or maybe low double digits.

There is a leather covered inner floor piece for the 230SL glovebox that is glued down OVER the four lower screws that mount the glovebox to the dash.  The BBB also shows three upper screws attaching the 230SL glovebox to the dash.

As far as for my car, after being reupholstered with leather in 1995 by a professional restorer, my lower inner floor piece was glued in place and the piece of leather on the front edge of that floor piece was folded down and glued to the bottom front of the glove box (captured between the glovebox and the hinge).  That obscured the fact that there was a separate glovebox floor piece, since the gap between the lower floor piece and the glovebox floor was hidden.  The glovebox, with the inner floor piece, the hinge, and the door were then installed and screwed through the floor piece, the glovebox bottom, the hinge and into the dash using all six of the holes in the hinge.  The two screws for the rivet holes were cut off very short because there were no matching holes in the dash.  The incompetence never stops!

At this point, I urge any one of you, with a 230SL and who care, to read and closely examine the first two photos attached.  The first is the BBB Page for Job 68-1 and the second is a magnification of Figure 68-1/2 on that BBB Page showing how the inner floor piece is NOT screwed down but, instead, is glued down and hides the four lower screws that attach the glovebox to the dash.

Interestingly, the photo does not show the heads of the two rivets under the lower piece, which leads me to think that they were not originally in the glovebox design and were perhaps added later to make it easier to keep the glovebox “assembled” with the door and hinge aligned and with the spring installed while installing the “assembly”.

Now here’s my question.  Do the instructions and photos in the BBB represent perhaps a “pre-production” stage of the car’s design?  Were the rivets in the first production car?  Was the inner glovebox floor piece screwed down in the first production car, or glued down as described and shown in Figure 68-1/2?

Regardless of the answer and because the BBB is very clear regarding how it is/was supposed to be assembled, I’ve made a new leather covered lower glovebox floor piece and have reassembled mine that way.  In my opinion, it looks nicer without the screw heads visible.  See the last two photos.

Tom Kizer

[66andBlue]

...
Interestingly, the photo does not show the heads of the two rivets under the lower piece, which leads me to think that they were not originally in the glovebox design and were perhaps added later to make it easier to keep the glovebox “assembled” with the door and hinge aligned and with the spring installed while installing the “assembly”.

Now here’s my question.  Do the instructions and photos in the BBB represent perhaps a “pre-production” stage of the car’s design?  Were the rivets in the first production car?  Was the inner glovebox floor piece screwed down in the first production car, or glued down as described and shown in Figure 68-1/2?  .....

Hello Tom,
nice sleuthing but I am afraid in this case a picture is not worth the words in the caption. There is something really screwy (pun intended) about this picture!  
The first telltale is the number of screws in the top of the box, the picture shows 3 while in reality there are only two!
Then the description of the screws: "oval head countersunk screws" in the bottom; if correct those would be DIN 7983. "Countersunk screws" in the top, if correct those would be DIN 7981.
I have marked up your pic to make this clear.

So what do the spare parts lists tell what kind of screws should be in these places and how many?  I made copies of the information provided in the first edition (Ed. A) of the 230SL list (July 1963) and the second one (Ed. B; Nov. 1964). Since you were also wondering about the rivets I included those also.

1. Hinge rivets: 2 each per hinge; no change till the end of 230SL production.
2. Each hinge is attached to the glove box lid with 4x  DIN 7981 "lens head sheet metal screws" 4.2x13mm; in Ed. A they were "galavanized-iridescent" and from Ed B on "chrome plated".  They were screwed into 4 clip nuts.
3. The box with the lid was held in place in the dash at the bottom by  4x DIN 7981 screws  4.2x9mm  and those were always chromed. and in the top there were  2x DIN 7981 4.2x13mm chrome screws. All screws went into 6 identical clip nuts.
In Ed. B the two screws in the top were replaced by DIN 7982 flat-top countersunk sheet metal screws, the clip nuts also changed, and 2 countersunk washers were added.

How was the bottom - MB-Tex or leather - glued to the bottom?
The spare parts list show a p/n 000 983 52 91 "stiffening felt cardboard 2mm thick" that is sandwiched between two layers of fabric and then glued to the bottom. Take a look at the photo here: http://www.sl113.org/forums/index.php?topic=14065.msg95596#msg95596

On my 1964 230 SL (and on the 1967 230SL) the bottom screws were visible, but of course, if you are not the original owner it is impossible to claim originality here.

So, which one is correct, the BBB or the spare parts lists?  I'll let you be the judge!  

[Scottcorvette]

On my June 64 230SL the hinge was riveted and certainly looked like it have never been off but who is to say. The hinge was riveted from underneath though and it looks to me like yours is on top.

I can't comment on the screws or covering though as mine had been done with some sort of flocking material and had no base board. I can't remember what screws were holding it but I will have them bagged somewhere. There was a real mish mash of fasteners in mine all around the interior.

[66andBlue]

Unfortunately I have only a blurred photo of the hinge in my 1967 230SL and on this one the rivet "head" on the bottom of the box is solid, no hole.

[Tomnistuff]

Hello All,

I have just a few more conclusions, observations and comments regarding the glovebox before I abandon the issue.  I appreciate your research, historical information and responses.

I have concluded that the answers to my two initial questions, “What happened to my two rivets?” and “Why six screws instead of four?” are: 1) the upholsterer who changed my car from MBTEX to leather in 1995 removed the rivets to upholster the glovebox and could not put it back together in the same way without replacement rivets or he forgot how to reassemble it correctly, and 2) after recovering the inner floor piece, he fitted it into the glovebox and then punched the holes in it by piercing through from the underside of the glovebox resulting in six holes instead of four.  Once the two rivet holes were punched through the inner floor piece, he had no choice but to “plug” the holes with shortened countersunk screws or to reupholster the inner floor piece.

Regarding the rivets in my newly completed glovebox, in the photo without the inner floor piece; the four screws shown are the ones that screw the glovebox to the dash.  The rivet heads (not visible) are covered by the black double-sided tape that I used to hold down the inner floor piece in lieu of adhesive.  The double-sided tape is less “permanent” than glue.

Regarding the BBB pages describing Job No. 68-1, I am still trying to understand why a supplement dated July 1966 and written specifically for the 230SL should be so obsolete at the time of publication, assuming that the removal and installation descriptions were written and the photographs taken years before when only a “pre-production prototype” was available for repair analysis, photography and documentation.

Based on the photos and descriptions, one thing is certain.  At least one 230SL was built with three glovebox upper screw holes and a lower floor piece that had no screw holes but was glued down over the screw heads using Dekalin adhesive.  The photos and instructions prove it.

Since the instructions do not mention taking care to keep the parts together during removal of the glovebox from the dash, it is probably reasonable to assume that the rivets were already in use at that stage of glovebox development, especially since it is so easy to damage the leather and the glovebox lid guide arm bezel if the parts become separated during glovebox removal.

Being a 34 year veteran of an automotive engineering design organization, I hate to admit it, but the rivets may be a another case of Manufacturing Engineering creating a solution to a Design Engineering created assembly problem. 

I suspect that without having knowledge of internal engineering and manufacturing conversations and communications dating from the time leading up to production launch, we’ll never know the reasons why the BBB appears to document a glovebox assembly technique that apparently never happened in production, especially since it has been 50+ years since it occurred.
 
I’m still going to leave mine with the inner floor piece glued down to hide the screw heads.  I can always fix it in about 10 minutes by using slightly longer screws and penetrating the floor piece leather if it becomes important.  The screw holes are already there under the leather.

These cars get more and more interesting to me, especially if I try to deduce the motivation of the engineers who designed and built them.  I'll just keep on reassembling my restoration and asking, "Why?", as I discover new things.

Tom Kizer