I would start by opening the rack, inspect and lubricate all the moving parts where there is supposed to be grease... it probably dried after all this years.
If that doesn't work you might need to replace worn parts (bearings etc..), and you will need to look for the parts one by one as the steering is not serviceable from Honda. Another option is to send the rack to one of the companies who service the rack (I think there are options on USA, Japan and Europe).