Grinding noise

[Robert.K]

SO i was driving to LA, when I stop at a toll booth. As I slowed down and rolled my window down, I hear grinding noise like something is spinning and trying to catch. I came to a complete stop and it got louder, then when I pulled of it went away. I got to the nearest store to check and didnt hear it again. Ive heard it before and thought it was my transmission. Got it checked, new filter, new fluid, still no results. I think its in my differential, but Im not sure if its coming from the back or front of the truck, but my guess is the back. Everytime i here it im not in a position to play sherlock holmes. But it only happens when I drive for a extended amount of time( 30 mins or more) and/ or consistantly over 70 mph. It scared the crap out of me since I stay about a hour and a half from LA, I had no service on my phone, and it was about 3 A.M!
My truck is also a 4x4, so that might play apart in it. Help!!!!

 

[CG-ITS]

Ha, I'm having the about same problem...

A weird grinding noise coming from the front end of the car after driving at higher speeds (>60) or for longer time (>30min). And it's only hearable below 40 MPH.
Also, it gets very loud in a left turn and disappears on a right turn.
This is in 2WD.
Also, while in 2WD the front drive shaft (transfer case to differential) turns freely. Is that correct?

Also, I noticed, in 4x4, I can no longer make turns while in Revers.

Any good guesses what may be wrong here?

 

[Cobra]

Ha, I'm having the about same problem...

A weird grinding noise coming from the front end of the car after driving at higher speeds (>60) or for longer time (>30min). And it's only hearable below 40 MPH.
Also, it gets very loud in a left turn and disappears on a right turn.

I don't know about the 4x4 stuff but your discription here describes what I had on my Tahoe. It turned out to be my front drivers side wheel hub beaing assembly.

 

[CG-ITS]

Just to keep you postet:
I took the car to a friend's shop last week in Wichita and they called today, saying they located to problem, believing it to be the driver side fron hub assembly.

So we are going to replace that along with some other parts (O2 Sensor, tire pressure sensor front passenger side, serpentine belt tensioner & both inner tie rods) and see if that fixes the problem.

I'll keep you posted.

Thanks,
Chris