Sounds like you have the frozen up joints in the steering column. It is a very common failure in x5 and land rovers. External lubrication does very little. I tried all the suggestions - sprayed different stuff, hit it with hammer to loosen it up, etc. nothing worked except replacing the part. It is fairly pricey.
There are some pictures here -
http://www.xoutpost.com/bmw-sav-foru...nt-photos.html