[Creeker]

My bro-inlaw just did this very thing. He stripped his rear jacks using a 1/2" impact on their Cougar 5th wheel.

I'm usually not one to recommend anything from Harbor Freight but their Earthquake brand impacts are good tools. Not the Bauer brand. They are junk as expected, but the Earthquake with 20 Volt Lithium is a good tool. They were recommended to me by several mechanics at a trucking company where they use them every single day.