I don't think it is "wik-wik-wik." Yer truck is saying "quick-quick-quick fix me!" (Laughing).
Without some more information it is hard to diagnose noises, he** I can't even diagnose my own.
Could be:
1. One thing scraping on another, like a brake shoe, tire contacting something, spring in the seat bouncin' up an' down.
2. Bearing noise can be almost anywhere--front, back, drivetrain, etc.
If you hear it at slower speeds (10 to 15 mph) maybe have somebody ride in the back (or let 'em drive, if you're not afraid). Try to pinpoint the location.
If you have GOOD, DEPENDABLE jack stands, maybe try raising the rear wheels. Unfortunately, some noises go away when there is no load. Just don't crawl under the truck up on jack stands when it is running--ever!
