Power Steering Question

[Jcol]

I have a 2002 2500HD extended cab 2 wheel drive. When I first purchased this truck over a year ago the power steering seemed stiff. As I drove the truck and the weather got warmer the problem seemed to solve itself and I stopped noticing it. Suddenly the stiffness is back again. There is still some level of assist but it just doesn't feel right. When I turn the wheel for a right or left hand turn the steering wheel stays set in the turned position, by that I mean it doesn't try to return to the straight ahead position as most cars and trucks do. I have to turn it back to the straight position. After driving my wifes car I really noticed how stiff the steering on the truck is. I've checked the power steering fluid which is full. There are no leaks and the pump is not making any strange noises. Should I try an additive or should I just take it into the shop for someone to have a look? Thanks.

[jro909]

the intermediate loss of power assist is an issue from gmt-800s, i want to take it has to do with the booster system...and power steering dosen't have alot to do with the wheel returning to flat position thats the job of the front suspension components mainly, power steering is just a system that raises and lowers hydraulic pressure in different chambers when you turn...otherwise if its really cold out the hydro fluid in the power steering pump is probably thick...

[Shaners]

Oversize tires will cause some of those symptoms.