There is no adjustment on rack and pinion steering. If you're steering is sloppy or something I suggest you get an alignment and your front end checked.
My 1998 E320 has a shimmy when braking that feels like the front rotors. It isn't the rotors but it also responded to adjusting the rack tension. It is a star nut on the back side of the rack facing...
A rack and pinion is a pair of gears which convert rotational motion into linear motion. The circular pinion engages teeth on a flat bar - the rack. Rotational motion applied to the pinion (by the...