when i drive it sounds like metal scraping from somewhere in the rear. Its worse when i brake. when i back up it sounds like its dragging. also when i decelerate above 40 the car shudders till im below 40.

anyone know what could be the problem?

 

maybe your diff? maybe you should take it out and inspect it/change fluid ect..

 

finally got a chance to look back there. turns out that it was the caliper feeler gauge saying i need rear brake pads. and i find out that the rotor is warped. so i need to find new ones.