I have been chasing a steering rattle since I bought it months ago (GGH20). first port of call to replace the steering motor damper, but when I removed the power steering motor it had already been replaced, possibly by import dealer. next I checked the steering column and felt movement possibly from the U joints. Bought a new but cheaper than OEM intermediate shaft off the bay and it helped a little but still a bad rattle over rough road surface at lower speeds. So after researching its been noted that the large gear that mechs with the worm gear from power steering can wear. so I stripped it down and greased the two gears.
This quietened it down massively, but only lasted a week or 2. As a result I now know its the steering column at fault, so have ordered hopefully a genuine new column minus the motor, from Japan. From what I have read this is common enough, though the previous owner of mine lived along a Stoney lane so this may have been a contributing factor