REAR END / DRIVE SHAFT
There are only a few checks for rear end. Put the vehicle in
gear. Do you hear a clank? This loud noise could be the drive
shaft universal joints, which are located on each end of the
drive shaft connecting the transmission to the rear differential.
If you are able to rule out the universal joints, or U-Joints as
they are commonly know, the gears in the rear end could be worn.
Unfortunately, to diagnose the rear gear wear, the housing has to
be opened and is not something most used car shoppers can
undertake. Have a certified technician diagnose the problem.
Now that you have finally left the driveway, as you are
accelerating, listen for a humming or clanking noise from rear
end. This is especially true when you are on the highway and
accelerate then immediately decelerate. For a rear end with worn
gears the symptoms will be as follows: A whining or humming noise
at a steady speed or at coast down. Bad universal joints,
sometimes give you a vibration at high speeds in either the floor
or body of the car. They can also give you a squeak on
acceleration. These components also have seals and bearings that
need to be inspected for leaks and wear. A rear end differential
uses a special fluid to lubricate the gears. This level should be
checked periodically, like any other fluid in the vehicle.