Old murray rider. Mod 42813x14a. Replaced steering gear sector awhile back and now the steering is slipping again, gears appear all right. Thanks for any help

My Murray has a steering bushing that mounts to the frame... the steering shaft runs through it, with a pinion gear in the bottom of the shaft... my steering stripped out and when I took it apart, I noticed that the pinion was oval shaped... worn out for years of steering... it is supposed to be tight around the shaft... a new one costs about $10... hope this helps