power steering fluid

2007 Hummer H3 3.7l i5 (122,XXX) miles Truck started making a whining noise when turning steering wheel, from previous experiences I first checked the power steering fluid and the fluid level was good. Checked parking spot for any PS fluid on the ground, but nothing found. Rack and pinion seems...

I have problems with the power steering only when parking or off-road. I have checked the fluid and its fine, I also haven't noticed any leaks. I started to notice this after my fun day of driving through a lot of snow, so maybe they're connected some how? I also just posted a thread on my...