My e320 is has some "play" in the steering (travels a bit at speed). I put it up and inspected the tie rods, ball joints and steering linkage. All of these components are in working order and nice and tight. the problem is that when the wheels are straight there is nominal play (1/4 of an inch or less) when i turn the wheels completely to the right the steering is very tight with virtually no play. When turned to the left however there is almost 2 inches of play at the drivers side wheel only. It appears to me that maybe a gear in the steering column or gear box is screwed up. Any suggestions on what may cause this and what components to inspect?

Thanks

Gary