You didn't say if it was 2 or 4wd, makes a difference. I have a 950 as well. Start by pushing the front tires back and forth, any play ?? If not, there is a access port on the right side of the tractor to the steering box. in the center there is a nut locking a screw, this is your adjustment for play. The spec says the wheel should have about 1-2" of play. Jack up the front, loosen the nut and adjust that screw until you have about that play in the steering wheel. Steering should still be smooth with this adjustment. These steering boxes get tired over time and sometimes need rebuilding. No bushings, ball bearings. While you are in there adjusting the back lash, be sure to check the level of the gear oil, 90 wt.
Chris