A maintenance issue usually over looked by the manufacturers, on most lower cost lawn tractors, is the lubrication of steering components. We see the problem frequently when someone asks for those parts and it's often long before the engine is at the end of its life span.
The sector gear and pinion gear can be lubed with grease a few times / season but the pinion bearing is not that easy, especially on my LA-135. So to solve that problem I attached a a length of small clear plastic tubing to the steering shaft terminating it at the bearing. The upper end I can see and reach with my oil bottle that contains bar and chain oil. A few drops in the top gradually gravitates down to the bearing while I'm mowing. There, I fixed it Mr. John Deere. An automatic oiler without the cup.