well i got the body bushing's all done only to be dissapointed with a very bad shaking coming from the rear. the question is how do i tell if it is a bad drum or axel's/diff problem any info is appreciated

Have someone fallow you while you drive slowly down the street. Have them look for a wheel that is wobbling. You may have a bent axle or wheel.

You can also put a jack stand under each side of the rear end of your car and let the wheels run to check for a bent axle; I found mine that way. For safety, it would be a good idea to have someone sitting in the driver's seat while you're checking it out.