I have a L5030 but recently had the same, or similar problem. Mine got so bad I had to continually spin the steering wheel to get the tractor to turn at all. It turned out to be a bad center seal in the steering cylinder. I isolated the problem by doing some testing that was suggested to me. I ordered a seal kit and after replacing the seals the tractor steers like new. The center seal was the one that was bad but I replaced them all since I had it all apart.