1970s 1974 Eldorado hood oil-canning

[danjarrett1]

Does anyone have any experience with the oil-canning affect of this huge hood going down the road? I have adjust the rubber hood adjusters, they seem to be fine, however, the left and right sections of the hood seem to quiver going down the road. No rotational vibration from drive train, just hood quivering along. I thought it might be a lack of support when it was designed but assumed GM would have solved that with extra bracing, I cannot see the structure on mine because of the hood pad. Is this just typical for the vintage of GM Caddy's? Also...the small Tri-angular rubber grommets (4) that are attached to the fencer where the hood ride are reducedto to age, I did try adding Addie too Al spacing there but no real result. Would like to replace those grommets if anyone has a source.   Thanks-Dan

[Dave Shepherd]

If possible, padding  like under insulation, between the bracing might lessen the effect, don't remember this being an issue back when I worked for Cadillac.

[TJ Hopland]

Its not something I have noticed but I will have to look for it next drive.  I wonder if yours is maybe too tight?  I have missing bumpers and insulation so my whole hood will move and rattle.

Or was 74 unique?  Did they have some new idea to shave 3 pounds of metal out of the hood structure? 

[danjarrett1]

 It sure...my Eldo is black so I see everything going down the road staring at this long long hood...it's as if there is insufficient branching from the factory on the hood

["Cadillac Kid" Greg Surfas 15364]

Dan,
between the hood "skin" and the cross bracing below the factory inserted a mastic type filler to provide the strength of the bracing without the noise and vibration. If in fact you are getting a rippling effect of the hood skin you might assume that the mastic has dried out and separated from the structure, allowing the hood skion to vibrate freely. you should be able to check this wothout removing the hood (insulation) pad.
Greg Surfas

[danjarrett1]

Thanks Greg, so can the mastic be replaced with destroying the hood? Or use another material?

["Cadillac Kid" Greg Surfas 15364]

If it has dried out and/or "disappeared" it can be replaced. If this is your case, check back and I'll try and find the remnants of the material I used.
Greg Surfas

[danjarrett1]

Thanks Greg, will do...btw, have you had any experience with converting the divorced choke with a electric

[Joe G 12138]

Does anyone have any experience with the oil-canning affect of this huge hood going down the road? I have adjust the rubber hood adjusters, they seem to be fine, however, the left and right sections of the hood seem to quiver going down the road. No rotational vibration from drive train, just hood quivering along. I thought it might be a lack of support when it was designed but assumed GM would have solved that with extra bracing, I cannot see the structure on mine because of the hood pad. Is this just typical for the vintage of GM Caddy's? Also...the small Tri-angular rubber grommets (4) that are attached to the fencer where the hood ride are reducedto to age, I did try adding Addie too Al spacing there but no real result. Would like to replace those grommets if anyone has a source.   Thanks-Dan

It is not a problem with all, but just some. My theory is that many people like to pose beautiful babes on the hood of their cars. If on one of those photo sessions the position is wrong, or the weight estimate off, that initial indent is prone to come back.

[danjarrett1]

That could have happened, who knows. The sheet metal that makes up this monster hood is not deformed in any way that I can tell, no indentations or warping, just long spans of sheet metal that tend to flex and quiver at highway speeds. One fellow did indicate that there was a foam like material between the gusset structure and the sheet metal of the hood. Over time, heat and wear, the foam-like material breaks down leaving a gap that can cause that to happen. I'm going to undo the hood insulation this weekend and take a peek at what is there. Thank you for your input. 

[Caddyholic]

I had this with my 61. The rubber pads on top of he fender under the hood were missing when I bought the car. I got new ones from rubber the right way and that fixed it.

[Big Fins]

Proper adjustment of all 4 hood resting pads will fix the problem. Start with new stem pads and go from there. Steele or Rubber the Right Way has them. Spray them with a little bit of silicone spray and they slip right on. Loosen the jamb nut and raise or lower as needed.

[danjarrett1]

I have adjusted the hood stops at the front of the hood, I even enhanced the 4 triangle-like rubber bumpers in the sides, still not enough. The hood just needs to be stiffened up a bit, but I will continue up to tweak. Also, anyone has]ce a source for the side rubber cushions?

[Big Fins]

Check with two that I mentioned above. I think that they have on-line catalogs.

[TJ Hopland]

Is the hood pulling itself down at the back by the cowl/windshield?

[danjarrett1]

No, the hood is not pulling back for force rear hood alignment problem. Did or some hood rubbers from caddy daddy. Will let you know if that resolves the issue. I do think that there is some material missing that was installed between the structure of the hood and the skin.  Have offered a new hood insulation pad as well, will remove old one to gain access and go from there

[TJ Hopland]

Mine does do it.  Never noticed before.  Now I wonder if its going to bother me.  I got home late so no time to investigate.   I don't currently have hood insulation so it should be easy for me to see if that glue stuff is still sticking between the bits.

[danjarrett1]

While wiping down the hood this morning I noticed that I could depress the hood on either side of the center stop at it would "oil can" where there is no bracing. One of the members suggested that a "mastic" type material was installed at the factory to deal with this. My car was repainted several years ago, they did a good job but they did not address this issue. I'm trying to identify what seaalent/glue/filler I can use to add solid structure. The simplest way to diagnose this issue is to gently press down on the hood panels at various location to see if the flex. Not sure how I'll fix it but driving down the road with the long shinny black hood flexing makes me crazy

[The Tassie Devil(le)]

One question.   When the car was repainted, was the hood dipped in a solution to remove all the paint, inside and out?

If so, it could be that the solution also removed the factory sealer that was placed between the frame and hood panel whilst it was being assembled?

Bruce.  

[danjarrett1]

I believe that is what happened. Hiw can I resolve this? Would expanding can foam for insulation work to fill in the gaps?