the lower housing on my F150 PS box (about an 1-2 inches above the pitman arm ) moves when i turn the wheels with the truck parked. The creaking noise is not from the pump, but from the lower housing as it's flexing. The frame has a reinforced plate attached. The steering geometry is secure and there doesn't seem to be any binding and the creaking noise doesn't happen while the truck is moving. Any thoughts on the issue.