I was in an old style boneyard on Friday. There's a lot of learning to be gained from looking at old cars and how they were made.

On my mind that day was what made Cadillacs different from other GM makes in terms of quietness. Turns out part of their deal was more seals than other GM brands.

I got some pictures to get a record of what they did that I could apply to my big Olds cars. The takeaway was that they used some additional seals & plates to dampen noise that Olds did not. I thought that was interesting. Here are some shots of decaying Caddies that might give you ideas too.

Here are some door jamb plates that they built into a 65 Sedan de Ville. These look mostly decorative, but add a nice bit of finish to the door jambs:

1965 Cadillac door jamb cover. Should be a decent starter template for an Olds, Pontiac or other GM's. The nuts are 5/16's"

From the front of the car:



These covers were metal. This one shows surface rust. 60's nice metal, not plastic.

They won't be too hard to gin up in aluminum & paint body color for a nice touch. My thought at the moment is to connect the inner edge to the body and line the outer edge in rubber seal to get a nice look and some noise reduction. Mock it up in cardboard for dimensions, then cut light gauge aluminum, paint & fit. Could be a fun saturday.

Here's a shot of mastic rubber cowl to front fender seals from a late 60's Eldorado. I suspect these dampened engine noise going to the cabin a bit. The material looks identical to what Olds used to surround radiators in 1966 and direct air through the rad. instead of around it.


Part of how Cadillac was "Standard of the World" long ago. Additional noise seals. Cool.

Symmetric on the passenger side:


Passenger side Cadillac cowl to fender rubber mastic seal. Not too hard to cut and attach.

Fusick sells this stuff by the sheet for not too many $. Should be another fun, quick project.

The only additional thing I know that's not captured here is that Caddy used additional flap seals on their door bottoms to keep out wind & water. They sat screwed into the door steel between the door panel and the flap hung down into the void between the door bottom and door sill.

I hope at least some of you think this is as interesting as I do. I like the idea that they built additional value into the higher priced brand rather than just badge-engineering it.

cheers
Chris

 

My 1962 Starfire has the same hinge covers and mastic fender seals.
Dennis

 

Very glad to hear this.

To your knowledge, were they factory?

 

Yes

 

My '69 GMC has fender seals also.

 

my 64 starfire had the hinge covers and fender seals also.

 

Very interesting. Guess it was part of the Lincoln v. Cadillac v. Imperial war for the King of the Hill title that was at its height from the 50's through the 70's.

 

My 66 Starfire had the heavy tar-like pads on the floor under the carpet. I replaced them with new ones and new carpet. I bet that made for a quieter ride, it was nice.