[murphyv310]

Vibration from the engine will pass through the driveshafts and can be transmitted through the hubs to the track rods and up the column.
This then begs the question, is the engine/gearbox mountings soft or is there play in the steering or suspension. Even sloppy front arm bushes could be the trouble as they are less likely to absorb vibration. Don't discount the fact that if fitted a steering damper could well be the problem.