Everything seems to work fine except a small slip in the track about every 30 seconds or so. Is there something that needs to be tightened?

The walking belt may be too loose. If you have made recent adjustments, lubricated, or had repairs, a belt can slip if not tightened. The belt can slip if you have too much friction or if the belt has been recently lubricated. If lube does not help your problem and you have exhausted all other possibilities, the walking belt is most likely worn out and must be replaced.
To adjust the belt: Less Belt Tension: turn both adjustment bolts on back of treadmill in a counter-clockwise direction. More Belt Tension: Turn both adjustment bolts equally in a clockwise direction. Center Adjustment (moves belt center to the left): Turn left-side adjustment bolt counter-clockwise. Center Adjustment (moves belt center to the right): Turn the left-side adjustment bolt clockwise.
An over tightened walking belt can raise the amp draw of your treadmill, contribute to seam separation on the walking belt, or both, so do not over tighten the walking belt.
You should be able to lift the belt in the center on the side by approximately 2” to 3”, if you cannot lift it by 2” to 3”, the belt is too tight.