Power Steering Fluid Or Power Steering Pump
When refilling the oil some may have dripped onto the belt which would cause it to start slipping badly and squealing loudly.
It sounds like the fan-belt is slipping.
possibly a bad brake...you should get all brakes done
If that's the extent of the complaint, check the serpentine belt and tensioner.
Power Steering pump my have a leak...
metal, right? Sounds like metal, yes.
the cv axle wasnt completely tightened causing the hub bearing to go out
rear differential got lube? rear wheel bearings?
Though there are several possibilities, by far the most common reason for that is a loose or glazed belt in the engine compartment.
Start with the most likely andeasiest to fix. Check your brake pads... There is a wear indicator on the inside pads (closest to engine) that will rub on the rotor and make a squealing noise to warn you that the pads are getting thin. When you apply the brakes the noise will go away a lot of the time. If the pads are new or not making the noise then I do not know what the problem may be.
May be nothing more than compressor belt is slipping or A/C compressor may be getting "tired" an may soon need replacement