How do you take slop out of steering on cub cadet 1806?

Sell it, junk it. Kidding!

Look on the steering box at the bottom of the steering shaft. There MAY be a screw sticking out the side of the box, with a jam nut on it. If so, jack the front of the tractor up so the front wheels can be turned fully from full left to full right (known as: from lock-to-lock).

Turn the steering wheel full left (or right, shouldn't matter) and then loosen the jam nut. Turn the screw in the middle of the nut clockwise (in) gently, until it bottoms. DO NOT REEF IT DOWN! Now back it off a little bit, typically 1/4 to 1/2 turn is plenty. SNUG the jam nut. Now try spinning your steering wheel back to the right. It should turn freely with no binding, and should go smoothly from full right to full left. If so, then you are done. If not, and it is binding, you must loosen the adjuster screw up until it turns smoothly from full right to left (or vice-versa). Any "binding" left will shortly destroy the internal steering gears.

Ok, now that we've covered that... That might not have even been your problem!

There are MANY things to look at, including tie-rod wear, spindle bushing wear, axle pivot wear, and steering box wear.

Does your 1806 have Power Steering? If so, that would be another thing to look at. For example, if either the steering cylinder or the steering motor are leaking internally, that can cause "steering slop".

I told you about the manual steering box, because that is the most common problem, espcially with Cub Cadets.

Good luck and Kudos, ~ AJ