zdad21921

I hauled a 3000 pound load in my 2002 F150 5.8L (6.5' bed) without trouble until I unloaded it. It developed a rhythmic low pitch rubbing/scraping sound which sounds like it is in the front of the truck (the rhythm seems much slower than the rotation of the wheels). I visually inspected everything underneath without noticing anything (no scrape marks on any parts of the wheels, no scoring of the rotors, no scrape marks on the drive shaft, no leaking seals).

Also, the load was on a 4'x4' pallet all the way forward in the bed. The fork truck set the pallet in the bed then pushed it forward to the front while the transmission was in park without the emergency brake on. The truck rolled forward a few inches before it held while the load was sliding forward.

Any ideas about what I did to it? Thanks.

gone postal

No idea what the noise is, but your description is no bueno.

The truck moved forward because you had a little tiny park pawl trying to hold a few thousands pounds of truck still while 3000 pounds of material and a few tons of fork lift were trying to tell it to move.

There's a very good chance something in the transmission was stressed to the breaking point.

zdad21921

That's my fear also. I have a mechanic friend who hopes to look at it tomorrow. Off the top of his head he is guessing, with reservations, that it is U-joint related. He wants to hear the noise it makes. Thanks.

zdad21921

My mechanic friend looked at it and after a ride and jacking it up concluded that it was a front wheel bearing. I could see the wheel movement he was talking about as he rocked it while it was jacked up. One mistake I made in my original post was the noise rhythm. He confirmed that the rhythm matched the rotation of the wheel which would make the bad wheel bearing diagnosis a little easier. Nice to have a mechanic friend. The hub assembly is ordered. I will let you know if the repair is the only correction needed.

zdad21921

Definitely the wheel bearing. The new hub went on easily and noise ended. With everything back on the movement of the wheel when rocking it back and forth was gone. Old hub came off with a little trouble. Impact wrench wouldn't break the bolts lose, using breaker bar with added leverage worked.