2006 F150 squeak when cornering

My 2006 F150 supercrew with 6000 miles squeaks when cornering. It's
very noticeable when in the mountains because of so much cornering. I
don't believe it is the breaks because I'm not applying them and the
squeak still occurs. Any idea's what I should tell the dealer when I
report the problem? Any idea's how I can figure out what the problem
is so the dealer won't keep asking for the truck? Thanks for any
advice.