I have 9,000 miles on my EQ, clean and lube the hitch head surfaces every 500 miles and it makes no noise at all. It did at the beginning but I wasn't cleaning and lubing as much as I am now. Keeping the hitch head surfaces lubed makes all the difference. Says to do that in the owners manual as well.
Loosen the socket bolts and swing the sockets side to side wiping down socket and head surfaces. Apply Reese ball lube liberally on same surfaces. Swing sockets side to side to distribute lube. Torque socket bolts to 60 lbs. Takes about 5 minutes and works wonders.