Happened to me after I replaced them with "PepBoys " brand replacements on my 92 D150. Drove me nuts when going down the highway and they would fold in from the wind. I tightened the heck out of them and it still happened. I finally bought a new pair from LMC Truck and it hasn't happened since I put them on.

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68 Dart 410 / 904
92 D150 original owner
21 Ram 1500 Quad Cab, Big Horn , Hemi ,4x4
23 Audi Q5
16 Honda HRV