My Craftsman tractor had developed a nasty habit of “sticking” when turning the wheel all the way to the left. The tractor is designed to turn left farther than it can right to give a good turning radius when circling trees or shrubs. After it would get stuck a great deal of force would be necessary to get the steering to come back to center again.
I took a look under the tractor and noticed two of the bushings that hold the steering rod gear against the sector gear was wobbling.
When turning the steering wheel to the far left the sector gear was jumping out of alignment steering shaft gear. Both the sector gear and the steering shaft gears were worn down as well. I looked at the sector gear mount and saw the two bushing above and below it were worn down and allowing the gear to wobble back and forth.
In the video you can see the slop in the sector gear and how it makes the tie rods move in an odd manner. As the sector gear moves all the way to the right (making the tractor turn left) it jumps the last set of teeth which was requiring the great amount of force to get the gears back together.
The bushing closest to the bottom was completely shot.
There was a large groove that had been worn into the gear shaft! This was the source of all the play in the system.
Replacing the steering shaft required dropping the shaft out of the bottom of the mower. I had to lift the mower up almost 2′ to get enough clearance to pull the shaft out. Replacing the sector gear did not require this, which was nice. While I was down there I noticed the tires had zerk fittings on them! Sadly they were completely empty. I filled them back up, along with a few others that I found in the manual, which would help with steering as well.