[eric19371]

I had that really bad on my wife's S40 only last month.

F/R Tyre was excessively worn on the inside edge, got that replaced, tracking adjustment seized (new arms needed) and as soon as that was done it had a really nasty bump steer but like yours drove straight.

Bump seemed to be worse with F/L wheel, got damper checked and there was a 'slight' misting of oil. Didn't seem to feel any different when I pushed down on the L/H or R/H corners but got front dampers replaced (plus mounts) and then problem solved. Plus the difference in ride was also so much improved that I thought the dampers or bushes on my own V50 were shot and had to get them inspected the following week.

If the tires are good I would put my money on the dampers being the culprit.