Could be from rust if it sits alot. Pull one wheel and look. Think about wheel bearing at the same time. All that work is not much trouble. Even utube will have folks showing how. I will guess here a shop would charge 2-3 hours labor and several hundred for parts (I have not done it in about 15 years)
2013 24RKSWE (27ft TT) Cougar 1/2 ton series
2013 Ford F350 4x4 CC 6.7 engine, 8 ft bed 3.55 rear end lariat package
Retired from Oregon State Police in 2011 than worked another 9.5 years as a small town traffic cop:
As of 05-2020, I am all done with 39 years total police work. No more uniforms for me.