I have a 04 FX4 Screw and the front passenger seat is a manual cloth seat. Now that the weather is getting colder, there is an annoying squeak coming from under the seat when driving on bumpy roads. or I can usually duplicate the noise getting into my truck and slamming the driver's door shut. If I slide the pass. seat forward a little bit, the noise kind of goes away. But if I slide the seat all the way back again, the noise comes back.

Any idea what it is? Seat bracket or something else under the seat? Thanks for any info.