I have a 89 camaro rs 305 T-5 transmission. The car started making a rubbing sound when I would be driving and the road would dip down then back up like a wheel being pressed against a fender well or something, I couldn't find anything anywhere and then I realized it sounded like it was coming from the transmission area and weight seems to be causing it. When I'm driving by myself the car is fine and I don't hear any noises unless I'm driving on an up and down type of road it grinds when the weight of the car is being pushed down. It has gotten worse but I can drive it as long as I am by myself with almost no noise BUT if a passenger is in the car it sounds like grinding hell the entire time, coming from right under the shifter area. In short, weight seems to cause a grinding metal against metal sound that's seems to be coming from the transmission right under the shifter. Anybody have any ideas?

 

Drive shaft rubbing on the parking brake cable (which is probably out of its little retainer feature and dangling lower than it should)

 

You were exactly right and are a genius!! lol My parking break works awesome now and it doesn't grind anymore. I would have never figured out that's what it was