Yesterday while I was driving on the freeway my car started shuddering. I usually don't go more than 45mph for the most part. Started hearing a creaking sound coming from rear-axle on the passenger-side as I slowed down at stop lights. Also the car is swaying slightly left and to the right. This seems to suggest suspension issues, so I checked....both rear bearings seem OK (wheels don't seem loose)...its possibly the rear-axle bushings. I've never done this job and have read online that its easier to replace the entire axle-beam instead of each axle-bushing. Is this true? It seems equally as difficult unless you run into issues with the bushing. Is this something beyond the scope of home-mechanic due to danger of car falling on top of you? (risk vs reward) Or is it something else entirely? Like the shocks suddenly squeaking (but why would the car sway left to right?) Car has 240K miles. Thoughts appreciated.