Bent tie-rods. Polaris machines are heavy, and as a result are hard on various parts like tie rods. Replace them with a stronger aftermarket part and you should have no more troubles. I rode with a friend who had two Sportsman 400's and he bent tie rods on every ride. Some people never learn. Then again, he was pretty rough on them. I think Polaris corrected the weak tie rod issue in the last four or five years though. If yours is newer than that, it might be something else.
I agree with that, and it could be the ball joints too. Aksoldier, your friend must be very hard on his machines. My sportsman is 12 yrs. old, has been rode hard and put away wet, and I have never bent a tie rod, and I run 27" tires. Weak front springs will contribute to this issue as well. I put a set of polaris scrambler springs on mine, problem solved.
He was hard on them. VERY hard. He rode them like he stole them, and didn't slow down for any obstacle. I rode Knik with him to the glacier and back 3 times before he moved to the lesser 48. He bent tie rods all 3 times.