Good Vibrations - Not!

[Michael Borisow]

Upon close inspection as to why the hood on my 69 vibrates at speed, I noticed a crack on the underside of the hood where the hinge is mounted to it. The crack is not in the hood itself, but the piece that runs across the front. What is this piece made of? Can it be reparied or does it need to be replaced. How is it attached to the hood itself?

Thanks in advance for your help!

Michael

[Joe L.]

Re: Good Vibrations - Not!

Michael-----

I believe that the underhood reinforcement that you refer to is made of fiberglass-reinforced plastic (FRP) material, the same as most of the remainder of the hood. However, it is a seperate piece. I believe that it was affixed to the hood by means of a high strength bonding cement which MAY have been done under heat and/or pressure. The hood was not assembled at St Louis but at the manufacturing plant of the hood supplier. Component parts for the hood assembly as-delivered to St Louis were NEVER available from GM and I am unaware that they are otherwise now available.

I would think, though, that you could repair your existing hood using modern, high strength epoxies. If done carefully and skillfully, such a repair might be indiscernable.

[Mark P.]

Re: Good Vibrations - Not!

Been there, done that.
When driving home one day I noticed the hood vibrating on the driver side front. Upon further examination I found out the underhood reinforcement was broken just where the hinge is mounted. I also found out that this place was already repaired. It was not done very good so I removed all the polyester filler and did it again. This was about 2 years ago.
Inside the fiberglass hood reinforcement there is a threaded metal reinforcement where the hinge is attached. When you repair the fiberglass, you need to grind down some of the fiberglass so you can laminate 2 better 3 layers of new fiberglass mats over the broken area. After laminating you sand down the area so it is level with the surounding area. This is because you want the hinge to be exactly in the same location as before the repair (obviously otherwise the hood wont match). When removing the hood from the car, be sure to protect the paint with tape around the edges. (And don't ask how I know this is necessary...)