Hopefully you have the adjustable TRW steering gear box...slide underneath and on the side of it, in plain sight, there is a 3/4" jam nut on a bolt with a straight slot notch in it's end. Loosen the jam nut (hold bolt from turning) and then turn it half a turn CW. Tighten jam nut and without the engine running, see how much play you now have. If still more than 1" you probably need 30 degrees more CW.
If there is no adjust bolt/nut you have a Sheppard box and nothing you can do other than replacing with a TRW.
I'm parking the following for future reference:
Shock Loads to the Gear
If the steered wheels receive a shock load, the shock forces are transmitted through the sector shaft to the rack piston, and on to the worm
shaft. The internal geometry of the steering gear causes the control
valve to send high-pressure fluid to the correct cylinder cavity to resist
the shock forces. By absorbing the shock forces hydraulically, the
steering gear prevents objectionable kickback at the steering wheel.
This post is my opinion, worth what you paid for it.
Our New ride...08 HR Navigator 45. A nice upgrade after 14 years with a 04 Dynasty 42.