Loud metallic clanging noise from drivetrain?

[Jeff532003]

Hi guys so I have a new problem with my 98. It sounds like so one put a nut in a can and is clanging it around under my truck. This happened once this past spring and went away as soon as I hit 55 mph. It came back the other day and is getting louder every time I drive. It is definitely drive train related. It's almost like there's a metal strap on my wheel whacking every time it goes round. The frequency of noise does increase and decrease with speed but the volume is always the same. It does not change with RPM which leads to me to believe its not transmission or transfer case related. Perhaps front diff? It's definitely coming from the front of the truck but I can't pinpoint which side. It is also making what sounds like a shifted tire belt vibration/hum at 45-55 mph which leads to me believe it might be something broken in the front end? I don't visual see anything without taking the tires off yet. Any clues or thoughts you guys have to help point me in a diagnostic direction would be awesome. Thanks in advance.
Jeff

 

[BIG GREEN FORD]

When you said humming it through me off, that's usually the front hub's .
Check list
*hubs
*nails in the tires
*front CV axels
*Last open front bumpkin and look inside

 

[Jeff532003]

Definitely not nails. It's much louder than that. Like there's a gremlin under there lol. I was thinking maybe hubs. I suppose ill jack it up and spin the tires to see if I can replicate it.
Could be something in the CV but I've always found that as more of a loud thud/clicking noise made worse when the wheel is turned to lock and this noise doesn't change when wheels are turned. It's the same in forward and reverse. If I am backing up at say 2mph it makes the noise maybe every three or four seconds. At 55 it's pretty much just one noise as it's spinning so fast.

 

[BIG GREEN FORD]

 

[Jeff532003]

To add to the mystery...
I was driving home from work this morning and it was real loud. Sounded worse than ever. At 55mph steady it lightened up and then kind of sounded like I was going 3mph with an occasional metallic tink. Accelerate a little and it's tinking away again. So I turn off the main road and decide what the heck let me pull in this dirt lot and turn on the 4wd. Only a4wd works because I need to change the motor but yeah. I turn it on, spin the wheels and make it engage. Put it in reverse and do it again. Repeated this once more, turned it off and spun the tires to be sure it was disengaged. Was wondering if it was sticking. I haven't used it since last winter. Anyway I pull out head down the road and all is well. No tink, no grumbling tire noise at 45-55 just a nice quiet rolling truck. So now I'm really confused. I admit I don't know tons about fords 4wd system with the auto lock clutches and all but is this a sign is front diff? How do the hubs auto lock? Could it be that? Any thoughts would be great. Thanks.

 

[BklynMamita]

I'm having similar problem .. Did u ever resolved and if so what was the issue