Power steering problem

[tavo80816]

Just recently, I have noticed that the power steering is stiffer than normal especially when I make moving left turns (90 degrees). Easiest way to explain it: when I am driving at say 20mph ready to make a left turn without stopping, the steering feels as if someone is trying to hold it in place while I try to turn (a lot of resistance), then there is a soft clunk sound, and then normal steering. That clunk sound was not there before.

I have checked the reservoir, and the level is good although I have noticed leaking of oil in my driveway (she never leaked before in the 2 years I've owned her). To me it looks like the common leak coming from under the reservoir is going bad which I can replace easily.

My concern is the clunk sound it does on left turns. I don't want to take it to the dealer just yet until I can get a better idea of what is wrong with the X5. Dealer is $165 just to diagnose the problem.

Any ideas?

Thanks.

2002 X5 4.4i 132k miles