I have a 1970 Chevelle SS396 w/ a manual 4-speed. Once I get up to 45 mph or so, a rattle develops that is related to the gear shift lever below the boot and console.It gets progressively louder the faster I go,peaking at about 60 mph where the rattle hits its loudest level and remains there regardless of speed.
I can minimize the loudness by shoving a block of foam packaging material down in between the gear shift lever and the left side of the console. However, it's easy to forget it's there until one needs to stop quickly and the piece of foam makes downshifting impossible.So far, two seemingly competent mechanics have looked at it, the first one stating that I need to replace the entire linkage (which seemed pretty extreme seeing as I could all but eliminate the symptoms with a nickel's worth of foam from the cockpit). The second one seemed very positive that he only needed to make several adjustments. He did manage to delay the development of the rattle to 45 mph from the 30mph it was originally and the peak loudness was less but still plenty annoying.
Has anyone gone thru this before? (I hope, I hope, I hope!). Any advice on what I might try now?
Thanks,
Rattled

drive shaft need balancing? U-joints bad? At what frequency is the rattle occuring? Engine rpm? Tire rpm? Things out of balance are the usual culprits for your problem.