Wheel bearing whistle

I replace my front left wheel bearing yesterday because it had a real bad growl. After I finished up I took it for a test drive. Now it has a loud whistle. After you drive about 2miles it goes away but once you let it sit for a while it will do it again. I need help I'm going on vacation on Friday and need it fixed.

 

few questions.
1. is it a whistle or more like high pitch sound?
2. Did you pack bearing with grease?
3. After pressing the bearing did you check if was rotating freely?

Best way to go about is is lift the front, remove the wheel, push brake pads away from rotor with flat screwdriver and spin the axle listening for sounds.
It could be anything.
Is your truck 4x4 or pre-runner?

 

It's a 4x4, high pitch sound, I did not pack it grease because its a sealed bearing. It rotated perfectly after pressing it on.

 

Its sealed bearing because it has seals on the front and back of bearing Unit. Still, it needs grease packing unless you are lucky to get one that was packed by third party. Normally those bearings come with just little grease to prevent rusting in storage.
Try removing wheel and checking if brake pads or maybe brake shield is touching something.
You can check if CV nut is still tighten to spec. Did you use torque wrench? How much you set cv nut to?