Unexpected rear steer on these cars is something loose in the back, either suspension links or bad subframe mounts. They will allow the wheel carreir to shift, and alter the camber and toe of the rear tires(s).

Usually worse one way than the other, the right side goes first for some reason.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!