Bad CV joint? This is common with other vehicles and they "click" when you're turning, but are fine when you're running straight.

Check for cracks in your CV boot for any cracks/splits. If the grease has spilled out, it should be apparent on the boot.

If this is the case, then you're in for a whole new CV joint assembly it would seem. That clicking sound is your joint starting to lock up.

Hopefully this is not the problem.. But something to check out.

Diogenes