Hi, I bought a used 2003 BMW X5 4.4i and it has a loose/worn front right side lower control arm with ball joint (just ike the image below). I first noticed it when I was driving 80 km/h (49 mph). The steering wheel was shaking, almost vibrating. I am trying to decide if I should drive my X5 a little bit longer or park it until I replace the control arm. I might be able to replace the control in a week or so. What should I do?

Morning Kyle

Welcome to the Forum

If there is vibration at such a low speed I would suspect not only the control arm but is the wheel Tyre out of balance is the fixing bolt and ball joint torqued correctly ? Also consider if changing suspension parts it is good practice to change bothsides at the same time. The job is straight forward just make sure the main bolt is Torqued up when the control arm is in the loaded postion (Weight on the suspension) or the bush will only last a very short time. Dont know where you are but in the UK most suspension parts are available from Motor Parts Factors next day at least prce I would expect to be around £25 to £30 per side. 

Worth considering is a complete suspension refresh as if one control arm is that bad other parts will  be worn as well 

Only you can assess the amount of risk as non of us can see/feel how loose things are

Hope this helps

Dave