Noisy top

I found out on a long road trip that driving my dad's '69 Wildcat over 50 mph with the top up and windows up is almost unbearable. At higher speeds the top starts making a "drumming" noise. Slow down it goes away. My dad has had other cars with larger tops (T-Birds and '66 & '68 Chevy Impalas) and they never made this noise at speed. The top is new, 2 years old, and took it back to the installer. He said he is more familiar with Fords and this was the 1st full sized Buick he had done but there was nothing out of the ordinary except that he was replacing a top that somebody started to replace but didn't finish. He ordered the new top from his normal supplier. We all agree the top is tight and doesn't poof up like it is loose/too big.

I know the easiest thing to do is drive with the windows or top down but we are planning on going on a 3 day trip so might need the top/windows up in case of rain. Trip is in 2 weeks and would really like to take this car.

Some adjustment that we don't know about? Some special part missing that didn't come with the car when we bought it?

 

It's time to check the air flow in your convertible. I caulked the seams in my trunk with black sealant and it helped some. The area between the rear quarter, wheel well and the trunk floor may be suspect.

 

Originally, the 'verts had a very heavy, insulated soft cover in the well. Many places tear it out, and just put a thin vinyl well cover in. There should also be a cardboard divider behind the seat to insulate trunk noise. I'm not saying that's it, but maybe a place to start.

 

That would explain why my new well liner billows up and obscures the rear window when I ride at speed with the top and windows up. I put a piece of PVC pipe in mine to weigh it down.

 

Right...this thing is like 1/2" thick, and maybe 3/4" thick over the wheel wells. Nobody repros them that I know of. Original tops had another layer of rubber like a tire tube, they were a LOT heavier. Currently, there are at least 2 weights of vinyl 'vert tops being sold. So that's just a few things that could make your 'vert noisy.

 

Ok, now I'm getting interested. Both of my convertibles are noisier with the tops up than down. They were both installed by the same shop, 20 years apart, so I'm assuming they used the same supplier. The shop had the best reputation for quality restoration in this area at the time. The wells are the flimsier type, not the heavy vinyl. The Wildcat will be needing a new top either this year or next, so I'm wondering, who makes the best and closest to the factory original?

Both of my cars drone like a DC-6 on a take-off run at highway speeds. Have to wear ear plugs while driving it's so bad.

I'm getting tired of flying a loud tent down the highway, and need something quieter.

 

I don't know where you can get one. When I look in my trunk, you see this like insulated "bag" that has diamond (maybe square) stiching. I remember somebody here (maybe DL) talking about this before, saying it should be in the judging rules or something like that. I assume most of these things were torn, chewed by mice, or just left off by the upholstery guys because it would be heavier and more difficult to reinstall. Maybe they tore where they attached to the trimstick. It's rare to see one now.

 

Air flow may have something to do with the noise. I remember driving it a few years ago and the top would whistle and you would crack a window down and it would go away. My dad re-did the weatherstripping along the header and the whistle (along with the leak) went away. Problem now is the window needs to be down more than a crack for the noise to go away. I will pass this info on to my dad as the car is back at his place.