How about listening under the front end when the car is parked, have a (trusted) friend turn the wheels? This way there is weight on the wheels and more force is required to run the pinion along the rack.. Put your hand on the rack, feel for vibration? If nothing else, check the rubber boots at the 2 ends to see if dirt might be getting into the rack.
2015 Leaf sold
2019 Leaf Plus S as of 9/30/19
Specialized Hardrock with Bafang midmount 750W
Liv Roam ebike
Stihl battery weedwacker and lawn mower