Change your power steering pump and get your front end checked out could be ty rods or axle problem too. If the car vibrates at 100km that s 90% front end. Or when it wanders all over the road thats gotta be the pump. If your lucky it might just be a seal leaking on the pump and not the pump itself. Whatever it is go to a scrapyard and buy the stuff needed for much cheaper. Good luck.
You can help the HubPages community highlight top quality content by ranking this answer up or down.