Power Steering Hard to Left ??

I have a 2000 Sub 2WD 1500 with 120K on it & it has become difficult to turn to the left espically @ low speed as if it has no power steering. I have seen alot of different post on this issue and seems that gearbox replacement is the cure. The pump seems to be providing the proper assit to the right but not left. Any body cured this symptom recently?? I would appreciate any advice short of buy a new truck -- thanks!

I have a 2000 Silverado that had the same problem except it was hard turning to the right at low speeds, and what you have heard for the cure is true. The steering box is shot. Brace yourself though because they are a bit pricey.

FYI friends -- A new gear box was installed in this Sub & the problem is fixed!
Thanks --