2006 F-350 Powerstroke Hard steering while driving

[lawnbizzz]

Steering seems to be working OK at idle however, when cruising down the road it almost feels like the wheel is locked! When the road comes to a bend, all I need to do is turn the wheel and when I let my hand off the wheel, it stays in the turned position. Normally the wheel would go back straight ( like rack and pinion).

This makes the truck very difficult and dangerous to drive on expressway, corrections to my wheel take actual effort and its very tight.

Now, I have been through 3 steering pumps (OEM and Napa) in the last year. I can also hear my serpentine belt squeak in the AM and only until the truck gets hot. Is it possible that I have a bad pulley that is causing these pumps to die? I drive the truck like a normal person, no mudding etc., truck is bone stock.

Why are these pumps dying and I still cannot understand why the steering works at idle but not at higher speeds. The belt squeaking is bothersome as well. Please help!

Eddie