I have just about completed the planned work on our driver. The only problem left to solve is the "banging" (metal on metal) sound when we hit a bump. The sound comes from the rear of the car. The shocks seem ok as they don't allow the car to rock up and down but once when pushed. Trimmed the end of the exhaust clamp bolt so it is not hitting on top of the spring. Replaced all the body/frame mount rubbers. Replaced the rubbler pads that mount under the frame to buffer the axle comming up. Removed the gas tank and checked everything and could not find anything. If anyone else has experienced this noise that sound like the car is bottoming out let me know what you found. The only think I can think of is possibly the mono springs are shot???? Also, went to a car show today and some one asked where the coffee cans were. I don't have them and don't know if I am supposed to have them. What is the purpose other than adding about 100 pounds for each can? Thanks for your help.

 

SS Conv.

I had the same issue. I only recently figured it out the source of this annoying metal on metal "clanging". It was driving me crazy! I nearly tore out a brand new multi-leaf springs and new shocks to find out where the noise was coming from.

Listen carefully next time you go over the bumps. I think you will notice that the sound is coming from inside the drums of your rear wheels. The mechanism(s) which operates the E-brake or parking braking is most like the source of your rattle. The bad news is that I have not figured out how to make it stop!

Two more things to check.

1. Make sure your spare and jack are tightly secured. I mean no movement what-so-ever as this has also caused me issues in the past).

2. Make sure your exhaust isn't touching the bottom of the rear fenders or the actual rear springs themselves. When I first got my car the exhaust system was not properly supported and the tail pipes were banging on the fender (just behind the rear wheel) and on the rear springs themselves.)

 

All first gen convertibles had what was referred to as "cocktail shakers" on the 4 corners of the body. Even though the frame was stiffened up, the body still flexed for lack of having a roof. Inside, the cocktail shakers have a weight on a coil spring and they're filled with a fluid. They acted as a vibration/twist dampeners while driving down the road. Yours sounds like a suspension issue to me though, since you're hearing metal on metal banging when hitting bumps. How are the leaf spring bushings (you didn't mention them)? If they're badly worn, you could have some metal on metal there.

 

Shocks and pass a bounce test but still have play in the upper or lower mounts.

Park brake rattle? That is a new on me. I have never heard a noise from a correctly assembled and adjusted set of drum brakes.

 

Gorn,

I don't want to hi-jack this thread, so will start a new one ...but I have a hunch that this may be the same issue SS is having.

Vic

 

SS Conv – Do you have a rear sway bar? if the metal to metal sound is a single and solid hit that makes you think another car hit you in the quarter panel when hitting a bump, you may want to check your rear exhaust pipes as they loop over the rear axle. If the rear axle housing is smacking the pipes, there will usually be a shiny spot on the exhaust pipe.
The coffee cans the person was inquiring about are called “cocktail shakers”. They actually work to counteract the shimmying you get from driving a convertible because of the lack of rigidity that comes from having a roof. The undercar bracing and bolt-in stock X-brace just doesn’t do enough to strengthen the body and chassis. If you don’t have the cocktail shakers and you’re having problems with shimmying, you should install a set of our subframe connectors that hug the floorpan like no other connectors on the market and a heavy duty X-Brace.

 

I had already planned on the Hotchkis X brace on my car but does the subframe connector require much modification to the car? I have a mostly original car and do not want to cut it up