Steering Wheel Shimmy

[DailyDriverMark]

Maybe a wheel weight flew off on a decent pothole. I'd look for signs of a missing wheel weight, when you jack up the car have someone rotate the tires while you watch the inside rim edge for signs of a flat spot. The factory steel rims are known to bend easy, yet cost 65 a piece.. (scam if you ask me)
Your LT probably has the upscale alloy wheels which might not get bent so easy.