I've noticed this a long time ago but have always ignored it. Want to go after it now and find out where that noise is coming from. Same noise on both of my 68s. So, here it goes. It's at slow speed driving, windows rolled down, clicking kinda like sounds like a small rock in a hubcap, but I don't have hubcaps (LOL). Pretty sure it comes from the rear of the car. The brakes are new and so are the drums. Could it be something with the axle? Wonder if it's a pretty common thing as it is the same noise on both cars.

Ramair68, wild guess, I once heard a clicking sound similar to what you described. Turned out to be a worn and dry u joint. ???
Ya never know!
Ron

Stones in the tires?

Thanks for your response, the U-joints are new so I don't think that's where the noise is coming form. I did order a set of rear wheels/axle bearings and will replace them hoping that may be it. I never replaced them in the 30 years I've had the cars.

X2.

What is the pace of the sound repetition- like every time the tire would make a revolution? Slower or faster?

I own four 'birds right now, and have owned 12+/- more since the late '70's, and I do not ever recall something like this. So no, I would say its NOT common.

I agree with the other comment/ideas.

Can you jack the car up and put it in drive to either confirm or omit a tire / rock issue? It sure sounds like that to me.

Loose wheel decorative center cap?

After that long, checking the axle bearings is a good idea anyway. I nearly found out what happens when one cuts through the axle. In 1977 I took mine into a Pontiac dealer for a grinding noise when turning right. The axle at the point of the bearing was less than half its normal diameter. And, many years ago one owner in the forum (or Firebird List) described having his wheel come off when driving.

I thought rock in tire too, but you say it sounds like a loose rock inside a hub cap...

Rock in tire is a click sound. "Snick Snick Snick" sound that varies with speed. Axle bearing more like a like thump. If you jack up your rear end, one side at a time and listen for sound you probably find it. If you have safe-t-rack rear end then jack up so both tires off the ground.

Block your front wheels in either case.

Also, check for loose mounting bolts/nuts on rear shocks.

jack up the car and turn the wheels, see if the noise is still there....then you can start finding it....if not, back to square one

Thanks for all replies.
I did the turning wheels by hand and trying to see if I could feel anything loose of excessive play, also ran it on jack stands but couldn't hear anything. Maybe it's only under weight when the tires hit the road. The noise is not real evident only hear it with windows down but definatley comes for the rear. I bought 2 sets of rear axle bearings and seals and will attack the bearings this WE. Hopefully the noise will go away. There's nothing in the brakes that's rubbing or loose, no stones in tires, and I don't believe the noise is coming from the differential or U-joints. Will post results after bearing change.

air rushing across things can do odd things. maybe there's an air turbulence that's moving a brake or gas line or something while moving

maybe try stuffing small pieces of foam between lines and body parts

just an idea if all else fails


there's nothing bouncing around inside the frame tubes?

good luck. bill v

OK, 'nother problem solved! So I did take out the axles and found the culprit. One side was still original but the seal has been replaced a long time ago and the bearing was loose. The other side the bearing has been replaced at some point that was loose as well and had a shorter spacer in it and was missing one of the thin metal gaskets and the bearing shim. I was lucky to get the old bearings off and non of them froze to were it messed up my axles. I replaced the bearings with Timkens, but [censored] it they are made in China now too! And its hard to find the OEM style "wide" spacers. So I went to O'Reily's and the National bearings have the correct .608 thick spacers that come with their China made bearings. So I took the Timkens back. The OEM bearings appeared to be Federal Moguls and they were bought by National, so I figured "as close to stock replacement " as possible and went with them. Worked out good, cut off the old bearings/spacers with cut-off wheel and was able to install new without a press. Had a long tube laying around and use it to drive bearings and spacers onto the axle shaft. All in all, it was a good Saturday. lol. quiet ride now, even better yet.