unusual cyclical friction

[footie11]

i have a '97 ltd. with roughly 82,000 miles. maybe a month ago i began feeling near my feet on the driver's side a weird cyclical friction, almost like something is rubbing against something else every two seconds when i am driving and i feel it with my feet. no idea what it is and it doesn't correspond with the rotation of the tires and it occurs when i am accelerating and when i'm not. any ideas/suggestions?

 

[toyoboy]

If you and i are in the same page that noise you are hearing is the front diff. Im a toyo tech and i have had tundras, tacos, and 4runs with push button 4x4. when I was trying to diagnos the problem I found putting atf in the transfer case decrease the noise. or try this, put it in four wheel drive and test drive it. then get back to me if the noise goes away.