could be, as mentioned above a wheel problem, my old man had it on his 16v renault cab, no viration felt thru the steering (though i expected it!) , think it turned out to be a bearing, i gave up when he said he couldnt feel it so he went and got a pro to look at it, the bearings didnt feel loose either though.
edit: my dad just told me it wasnt the bearing at all, it was the driveshaft and he could feel it! thats not what i heared at the time though!