Guest Steeleco Posted July 21, 2013 Share Posted July 21, 2013 Hopefully someone can help me with this problem. (63 Riviera) After backing out of the drive way and coming to say the first stop sign while putting medium pressure on the breaks I get a loud "Clunk" sound (one shot not continuous). Then it generally does not do it again for the rest of the trip. Any Ideas on what may cause this? This has been happening for a while and seems a bit worse now.Thanks, Link to comment Share on other sites More sharing options...
Guest Lasse Posted July 21, 2013 Share Posted July 21, 2013 X 2, have exactly the same issue. Brake reaction rod and/or it's bushings?Lasse Link to comment Share on other sites More sharing options...
RivNut Posted July 21, 2013 Share Posted July 21, 2013 Brake reaction rod and/or it's bushings? LasseThat would be the first thing I'd check. Link to comment Share on other sites More sharing options...
Guest Steeleco Posted July 23, 2013 Share Posted July 23, 2013 Hey guys, the Reaction Rod looks tight although rubber bushings are old and compressed. The wife and I both think the clunk comes from the rear or just behind the door. Any other suggestions? Thanks for the help. Link to comment Share on other sites More sharing options...
Jim Cannon Posted July 23, 2013 Share Posted July 23, 2013 I have this exact sound on my '63. It has been there since the day I got the car in 1999. It can be quite loud.As described in the original post, I get it on the first good, hard application of the brakes going forward, after applying the brakes going backward. After that one time, I don't get it, unless I apply the brakes again firmly in reverse.Something is sliding forward and back under braking action.I replaced both of my brake reaction rod bushings. That did not fix it.The sound might be coming from the back, I can't tell. I checked everything back there and could find nothing loose. It sounds like it is coming from the front to me, but the frame transmits the sound all over the place and makes it hard to pinpoint.Without proof, my working hypothesis right now is that it is one of the front suspension pieces, like the upper or the lower A-arms, is sliding a bit forward and backward due to the torque of braking. Apply the brakes when backing up and the suspension piece slides one way until it hits a stop. Then apply the brakes going the other way and the same piece slides back until it hits the stop on the other end. I have not been able to ge tin there and pry on anything and get it tp move, though.I don't think it is moving far, just enough to make a clunk noise. A shop that specializes in front suspension work (an old shop that used to work on GM cars in the 60s and 70s) has probably seen this before and could tell you right away from experience what it is. I have not followed up on that idea. Link to comment Share on other sites More sharing options...
Guest Lasse Posted July 23, 2013 Share Posted July 23, 2013 I'm glad (?) to hear I'm not the only one finding this a mystery. After all, if it's a mystery for Jim, what chance do I have!I suggested the brake reaction bushings, although I have myself changed 90% of the front end bushings and joints. And the "clunk" is still there. I just thought I did such a crappy job with it and that's why noise is still there.The "clunk" manifests itself just as described earlier. After backing up the driveway, and when first touching the brakes when moving forward. But I think it comes from the front. Or then I'm not objective here as my main suspected culprit has been the brake reaction rod bushings.Interesting!Lasse Link to comment Share on other sites More sharing options...
JZRIV Posted July 23, 2013 Share Posted July 23, 2013 Is the sound coming from the front, center or rear of car. Can you "feel" it as well as hear it?What suspension components hae been replaced on the car? Link to comment Share on other sites More sharing options...
Guest DRM500RUBYZR1 Posted July 23, 2013 Share Posted July 23, 2013 U joints yoke or trans mount?seems like you all pursued and ruled out the usual suspects.Marty Link to comment Share on other sites More sharing options...
RivNut Posted July 23, 2013 Share Posted July 23, 2013 I was thinking that perhaps it could be the rear control arm bushings. Once you get the arm in a forward thrust position it remains there until you reverse the thrust and move it the other direction; or perhaps some elongated holes where the two half of the rear control arms bolt together.?????Ed Link to comment Share on other sites More sharing options...
60FlatTop Posted July 23, 2013 Share Posted July 23, 2013 The original track bar bushing has a webbed open design. If anyone has removed a spring or let the rear end extend below the limit of the shocks it could be torn and allowing the track bar to whack around. The replacements I have seen and the one I used are solid. Its a big bar and makes a big bang when its loose.Bernie Link to comment Share on other sites More sharing options...
CheezeMan Posted July 24, 2013 Share Posted July 24, 2013 The original track bar bushing has a webbed open design. If anyone has removed a spring or let the rear end extend below the limit of the shocks it could be torn and allowing the track bar to whack around. The replacements I have seen and the one I used are solid. Its a big bar and makes a big bang when its loose.Berniethat gets me to think a bit... my '63 also does the same and has since I last replaced the rear brakes, but I swear that the sound is coming from the front (my wife also confirms it is from the front). I recently replaced the track bar bushing with those solid ones, and still have the thunk.I think that Jim is on the right track that some suspension component is moving a bit under a high amount of force.The mystery continues. Link to comment Share on other sites More sharing options...
Jim Cannon Posted July 24, 2013 Share Posted July 24, 2013 U joints yoke or trans mount?seems like you all pursued and ruled out the usual suspects.MartyYes, I had them all out and inspected or replaced. No change. Link to comment Share on other sites More sharing options...
Jim Cannon Posted July 24, 2013 Share Posted July 24, 2013 The original track bar bushing has a webbed open design. If anyone has removed a spring or let the rear end extend below the limit of the shocks it could be torn and allowing the track bar to whack around. The replacements I have seen and the one I used are solid. Its a big bar and makes a big bang when its loose.BernieYes, I replaced the track bar bushings with new solid ones. No change.It greatly improved the handling because it keeps the body more centered over the axle, but no change to the clunk. Link to comment Share on other sites More sharing options...
Jim Cannon Posted July 24, 2013 Share Posted July 24, 2013 I was thinking that perhaps it could be the rear control arm bushings. Once you get the arm in a forward thrust position it remains there until you reverse the thrust and move it the other direction; or perhaps some elongated holes where the two half of the rear control arms bolt together.?????EdIt could be. I inspected all of those parts and confirmed that the control arm bolts are all tight. I am not replacing the rear bushings just to see it that was it. A big job and very costly parts. Link to comment Share on other sites More sharing options...
60FlatTop Posted July 24, 2013 Share Posted July 24, 2013 If the reaction rod bushings are tight and the upper control arm bushings are OK, the only wiggle spot left in the front is this lower inner bushing. At 50 years old the rubber can be bad. I remember making a special driver to install my new ones. I'll look around the garage for it.The picture is light in the bushing area but you can see it could easily be overlooked on an assembled front end. Link to comment Share on other sites More sharing options...
Guest Lasse Posted July 25, 2013 Share Posted July 25, 2013 Bernie, I replaced those ones also with no effect on the "clunk". And that task nearly drove me to insanity even though I also made a special tool for it... Link to comment Share on other sites More sharing options...
Guest DRM500RUBYZR1 Posted July 25, 2013 Share Posted July 25, 2013 At this point, I suggest looking beneath the seat for that missing bottle of Jack Daniels that occasionally rolls around, as only that bottle can do.A clunk of that magnitude has to be coming from a significantly sized part moving.As you rule out suspension parts, I keep getting back to drive train.Have you looked at the engine mounts?You may want to consult with a exorcist if nothing else can be found.Perhaps it is a ghost of an assembly line worker from the plant just messing with each of you.I'll continue to explore serious possibilites.I and others i am sure are now intrigued by this.Good Luck!Marty Link to comment Share on other sites More sharing options...
RivNut Posted July 25, 2013 Share Posted July 25, 2013 Many moons ago on the first Riviera I owned - a '66 back in the mid 70's, I had a clunk similar to what you're discussing. We found that a loose bolt attaching the rear control arm to the frame had caused a hole to be elongated in the frame. The mechanic welded a larger washer to the frame and made sure the bolt was tight so there'd be no movement. I never had another problem in the two years I owned it. Ed Link to comment Share on other sites More sharing options...
tjthorson Posted July 25, 2013 Share Posted July 25, 2013 This may sound silly - any chance of movement in the trunk by the jack, spare, or lug wrench? Link to comment Share on other sites More sharing options...
Martin Monsjou Posted August 25, 2013 Share Posted August 25, 2013 High there, And? Was it something in the trunk? I have a "klunk" in the front ...took a while but finally..it was the exhaust against the bottom of the car when pulling up.Succes in finding and solving the problem!Martin Link to comment Share on other sites More sharing options...
Guest Steeleco Posted August 25, 2013 Share Posted August 25, 2013 My clunk is still there. Seems like it makes the sound when I stop while going forward after backing and stopping and it will do it upon backing. Then it does not do it again unless I back up or do a serious accelleration from a dead stop and then brake. Link to comment Share on other sites More sharing options...
Guest DRM500RUBYZR1 Posted October 23, 2013 Share Posted October 23, 2013 Any updates?Problem solved? Link to comment Share on other sites More sharing options...
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