Mysterious grinding sound from wheel hub area.

[my_gst95]

There's an odd grinding-like sound from the passenger side front wheel hub area I can't seem to locate. It sounds similar to a warped rotor grinding on a backplate, but it doesn't follow RPM. If I go over a bump sometimes, I can reproduce the sound audibly louder, so I know it's something that is loose and not neccisarily just grinding. If I bounce the car up and down above the wheel area, I can slighly repoduce the sound as well. I've already checked:

*Wheel hub seems to be ok when jacked up, can't twist or shake assembly inward-outward.

*Rotor doesn't seem to be grinding on the backplate, shims, or anything else.

*Axle was replaced a couple of months ago.

*No wear or grinding marks on the lowered strut or the spring.

*Free-reving the motor in Neutral at park doesn't create the sound, so I know it isn't something loose in the bellhousing of the transmission

The only thing I can think of is when I removed the old rotor and put on these used cross drilled brembo rotors, there were 2 small bolts holding down the assembly the rotor sits on top of. I had to take out those 2 bolts in order to install the brembo rotor because it didn't have openings to allow the rotor to sit flush...but the stock ones did. I just figured the lug nuts would push up against the whole assembly hard enough to not warrant any flex and warp. Are those 2 small bolts neccisary?

Any suggestions on what else I can check?

my_gst95

 

[my_gst95]

Wow that was the wierdest thing I've discovered to break and come loose. It ended up being the outter ring of the transfer case where the driveshaft plugs into. I jacked up the car and spun the wheels and it was loud even then. Is this a common occurance for 1g transfer cases?? Duct-tape is the temporary fix til I put in my 23spline transfer case and output shaft.

my_gst95