[MBZ] 300CD left rear clunking

[Luther Gulseth]

My coupe has a rhythmic thump coming from the left rear.  I jacked it up  
and tried to shake the tire, do not feel any play in it.  I tried to shake  
the axle shaft, and it seems firm.  I noticed this Tues night after being  
on the interstate.  Pulled away from a stop sign, and heard it the moment  
the car starts rolling.  Haven't been above 30mph yet.  What would cause  
sounds like this?  TIA all,

Luther, again-no rolling cars.....
--
Luther  KB5QHU
Alma, Ark
'83 300SD (happily running WVO/diesel mix)
'82 300CD (Slate grey, black MBTex, WVO/D mix)
'82 300D '90 300E (both parts or can run??)