First of all if you jack the front of the tractor up so the front wheels do not touch the ground how does it steer? Have you checked the pressure for the steering at the flow divider? Have you checked the flow divider spool to see if it slides freely in the bore/ Do you have Saginaw steering or a replace orbit type steering unit. On the smoke: Pull the exhaust manifold and see which cylinders the smoke comes from first. Do they all smoke&gt; How does it start.