rear end knocking noise

["Huw Upshall" <hupshall@triumphcars.com>]

I was driving my car and I have a knocking noise comming from the rear
end - turning corners makes it louder.  Sounds like a classic u-joint to
me but I jacked the rear of the car up and inspected the joints.  They
looked tight to me.  Is there anyway to check these u-joints?