Yes, sounds like the centering valve on top of the power steering unit. Full procedure is in the factory service manual, but the gist of it is to loosen the bolts holding it, (don't remove them, just loosen them) then tap the valve up or down (forward or rearward) on the steering box till it works like you want it to, then tighten the bolts back up. Sounds like it's all the way in one direction, and needs to go back the other way. use light tapping, A little bit goes a long way.

Tav