The problem is their independent rear suspensions. First seen appearing on 1963 Corvettes, this "trailing arm" rear suspension, which also features a transverse leaf spring, was an improvement over the live axle of first generation of Corvettes and enabled drivers to drive their cars fairly "hard" on race tracks and smooth roads. However, unlike modern multi link or even double wish bone suspension systems, trailing arm suspensions are marginally better than live axles when it comes to real world roads. What's more, its rather complex design was prone to failure and repairing it time consuming and very expensive. The failure points are the bushings at the end of the arms and the metal shims that hold the arms rigid against the frame of the car. This is not the rear end from our car.
However, the shocks are dead and the rear end feels dangerously loose, it's as if it has a mind of its own. There's also a guttural groaning that comes from back there even after the shortest of jaunts that has me concerned. It's gotten so bad that I hear the groaning even backing out of our garage.
What I've surmised is that on our car the bushings (arrow) on the trailing arms need to be replaced in addition to new shims needing to be installed. The groaning stems from the arm rubbing against the frame of the car. It's really bad on the driver's side. To do this overhaul correctly will require the complete removal of the "TA" from the car. Now, I love a good project but this will test my humble mechanics skill sets and will be, without doubt, the largest and most complex automobile project I will ever undertake. Incidentally, I guesstimate to have the job done professionally would run me well over $2,000 if not clost to $3,000. If I do it, it might run me $150. $200 tops for parts. Good thing I'm "handy". The above picture of a "TA" is not from our car.
My wife and I enjoy driving our Corvette but not nearly as often as we'd like. The punishing ride of dead shocks along with the rear end flailing about in any direction it wants to go in except the direction the rest of the car is going makes our Little Red Corvette quite an exhausting handful to drive. She sure is pretty, though.
I plan on making the "TA" rebuild Job 1 this winter. Wish me luck. Something tells me that I'm going to need it.