https://www.toro.com/en/parts/partdetails/?id=28013
Click on manuals, then service manual, then second service manual 492-4736, then section 5 page 3. If you don't feel comfortable working on steering, I would take to reputable Toro dealer. Tires, brakes, & steering are the three most important parts when it comes to Safety.
I'll share a short but true story: After 4 yrs. of U.S.A.F. being a jet engine mechanic, 2 & 1/2 yrs. as asst. crew chief, I decided to become a diesel mechanic on 18 wheelers. I worked for largest Ryder shop in state being Doraville, Ga. just north of Atlanta. Had tractor come in that would not hold road, tractor would turn to the right when holding steering wheel straight, you would have to turn wheel to the left as fast as you could to keep on road. Supervisor had top 4 mechanics try to find problem, to no avail. He had me stand on catwalk, just behind cab, while he drove down 2 lane roadway in front of shop, wanted me to look at rear suspension, axles, etc. With tractor back in shop I placed a large rubber scotch block in front of left front wheel, approximately 3 feet in front of wheel. I had a co-worker look at left front suspension spring, while I drove tractor hard & forward into rubber scotch block sternly, & sure enough bushing & solid steel pin inside of eye of left front spring were broken causing tractor to dart to the right. I'm a praying man & was asking for help from above. The driver of that tractor had to use a rental for approximately three weeks & was glad to have his old truck back.