Still having vibration problems...NEED HELP!

Hey folks, I have an 86 GT, all stock, stock gears etc. When I slow down to a stop, it feels like the rear end is vibrating...kind of like when you hit those rumble strips on the emergency lane of the interstate, but not that severe. Any ideas on what to check and how?
 
If brake pedal related, warped drums, maybe?

Other ideas....rear wheel bearings bad, loose lug nuts, worn axle bearing surface, damaged c-clip groove on axle, bad control arm bushing(s), worn rear shocks, rear brake hardware damaged or missing, low tire pressure, tire with a separating belt, low diff fluid....

I dunno, outta ideas......
 
Have you rear drums resurfaced or replaced, then the brakes adjusted, if they are still in good shape. If not replace the shoes and hardware also. This will make a big difference, its cheap and it is also regular maintenance. If it was anything related to the rear axle, springs, or control arms you would also have noises and vibrations while driving forward or on acceleration. A local shop could do this for around $100-$350, if you have the skills and tools u can do it for around $40-$120.
 
I need to check a lot of things. It doesn't seem to do it all the time, so I don't know if it's the rear end or not. Maybe it is, because it doesn't seem to do it when the car is cold...I don't know. No time to mess with it! GRRR!

I did notice the bushings on my quad shocks are shot on one side...maybe this is it. Thing is, they've been like that a long time.

Thanks for your help guys...I appreciate it.
 
Using a standard process of elimination like you would when doing a diagnostic. Think about it like this, if it only happens when braking its in the brakes, if you feel it behind you then it is the rear. As far as it being intermintent it will more than likely be in you rear brake hardware. Something like a broken spring, frayed cable, stretched retainer, or the brake shoes could be "corkscrewing", mechanic term.