Nowhere Man

when you first drive the car, it has a loud squeak sound. looking over the U joints they look brand new. while the bushings are mostly original, they are still there all together. if you jack that car up and a jack stand in front of the wheel and push on the rear of the car you can see a deflection of the rear body to the door. the frame is solid with only signs of scaly rust. the bird cage is solid all around. what I cant see is the luggage stop and how it meets at the B pillar. but that feels solid hitting the carpet. what am I over looking?

dplotkin

Body mounts are.....condition?

Dan

Nowhere Man

original condition, they are there but cracked and a little flattened out

phil2302

Could it have to do with the fact that convertible bodies just flex more than coupes. Squeak could be unrelated to body flex.

Nowhere Man

very well could be. the squeak goes away after you drive it for a while. buts its very noticeable when you start off.

dplotkin

I have a fully restored convertible and it drives like a new car. Squeeks come from the top, when up. When down, no squeaks. Try it top down to rule out the cloth and steel umbrella over your head known to make noise. My vert does not squeak top down.

My guess is your body mount(s) have flattened and are allowing movement. The convertibles with less bird cage than a coupe and no top holding the corners together is going to exhibit some torsional and longitudinal flex which is exacerbated by worn mounts.

Dan

Nowhere Man

it does it both top down and top up

warrenmj

I would tell you to remove your hearing aids which would resolve the problem for most of us, but I know you’re too young for them🍻

ChrisBlair

Goes away after it is driven a while?

Could coincidentally be body mounts but the noise going away after a period of drive time doesn't make sense to me.

dplotkin

Things change as they warm, or cool. I'm not married to body mounts being his problem but I am engaged. He sees movement of the aft end relative to the door opening, he has a squeak and he reports his mounts are old and flattened. Body mounts come to mind.

Dan

66jack

How's your door gaps?

Nowhere Man

door gaps are where they should be for a St. Louis build quality. The noise sounds like it should be coming from the drive line/ suspension but I don't see anything abnormal when looking all over. I will admit the body mounts are suspect and could use a change due to age and that that will most likely help the flex part but the squeak is very confusing to me. I have no clue when the last time the trailing arms were serviced but there is a sticker on the bottom that can't be read and surprising the shims still have a white GM part number sticker still on them. So by guess they have been out before. No clue when those shims were discontinued though. I wish I could read the sticker on the t/a.

dplotkin

Can you get it on a 4 post lift so you can load the chassis while being under it?

Dan

Nowhere Man

Sorry no 4 post lift to use.

ChrisBlair

Roger that. This is why it makes no sense to me. What's the heat range past ambient those mounts actually see, from driving? There's not much CTE going on there from the exhaust. I've had many squeaks out of classic GMs. They are maddening.

It's logical that CTE is involved, but if the mounts are also involved I'd be interested in the temp range they have to see to stop the noise.

So the questions being begged are: does the car make the squeak when going over a bump? Running on smooth road? Taking a left turn or right? When one corner of the car is manually pushed down?

The car might make no sound whatsoever when the outside temp gets over 70*F or so. Those are fun squeaks lol

OH- additional thought: I have a car with an optional suspension, with urethane bushings in the anti-sway bars. Under 50*F they squeak a lot.

Has anyone 'upgraded' this car's suspension? Nothing needs to be "wrong" to make noise.

67's

Keith, Floor sag?

Nowhere Man

Tom no floor sag or evidence contact on the floor. The car has rubber bushings though out. So no poly.

dryak

Turn up the radio.

OK, that’s no help, but I couldn’t resist.

Vettrocious

I’d look at all the old rubber mounts and bushings as possible sources. Old rubber doesn’t flex like it should.

tuxnharley

My 67 convertible has squeaked one place or another since I got it in 1971. I just fix one thing at a time and live with the rest, convincing myself that it’s part of the charm of the car! LOL