I've had a couple of Monteros with that annoying metallic rattle. Both times it wasn't the bracket you are referring to, it was the stone guard that was around the front of the rear driveshaft. I just undid the driveshaft by removing the four bolts at the rear u-joint, unplugged the front from the transfer case (gear lube will come out), removed the part and plugged the shaft back in and bolted up the rear again.

Rattle gone.

I'd double check yours. Give it a wiggle. I've never missed having mine there.

John B.