I guess that without any information as to what year/make/model mileage etc I cant make any guesses, but:
First I'd look at the mileage then check to see what should be replaced as per the factory service manual. Then I'd check with the customer to see if any of it has been already previously serviced/replaced and go from there.
I am sorry about the lack of info. The truck is a 1993 F-150 4wd. But I figured it out, the trouble was only happening when the steering wheel was turned... So like Nissans, Fords have steering stops and all that was needed was some grease on the stops!!!!!