My drivetrain issues, what is going on?

[davetheman81]

Hey guys and girls im a newb to drive shafts and i was hoping someone might shed light on this issue. Well since the build i have been having many drive train issues, it all started when my t case seized up, i was doing about 10 mph, i had bruce replace it and the seal and he checked the center diff and the shaft had no play or gouging in it. I then noticed my yolk was leaking so i replaced the whole drive shaft with a better looking driveshaft and new yolk, and put in a 4 bolt rear end. Ever since then i have always noticed a ratle/scrapping sound in the rear end only during constant speed, it would disapear with acceleration and deceleration, i removed the fluid from the rear end last night and it was clean, and replaced it again. Then took a drive and mysteriously now i get a scrapping ratle noise from the frnt end to now, sounds like its directly under were the passengers nees would be, it sounds like a garden rack on pavement somewhat, this noie how ever only shows it self staying a certain speed like the other noise but also inbetween shifts, and last there is a suttle whine from under the car for the first 1k rpms in1st and 2nd gear. The exhuast or any heat shield is not scrapping but i did notice the driveshaft carrier bearings are completly trashed, you can move the driveshaft about .5 inches in any direction, could this becouse the driveshaft to have backlash and make the car make these noises? If not any idea? Thanks