Since we don't have confirmation of what chassis you have, guess I'll add a note that affects all diesels and could apply to gas rigs as well (I don't know the gas rigs part).
You should NEVER be able to turn the wheel far enough to contact the axle stops. There should be a 1/8" gap between wheel max cut angle and the axle stops. You have enough hydraulic assist that you could potentially bend parts if the wheel cut angle contacted the stop. I know on our last coach, I adjusted the max cut angle (Sheppard steering box) and verified that there was a gap at the axle stop.
And, if a diesel, it is quite likely that you have a filter in the system. Verify with your chassis maker. If so, change fluid and filter(s).
