I have an 08 f150 4x4. It is starting to have a low rumble at takeoff up to 45 or so then also when slowing back down. I believe it's on the right side. How do I check to make sure this is the problem before I buy wheel bearing assembly and repairing. Any help is appreciated.

 

have you jacked the truck up and rotated that tire to see if you hear any noises? Check out your CV joints and boots too.

 

I jacked it up and spun them and heard nothing. And didn't feel very rough.

 

I had my front passenger side right go. jacked it up and spun it and couldn't hear anything but replaced it and back to normal. I ended up doing both sides. you have to get the whole assembly if your truck is 4x4

 

Jack the truck up, and while holding onto the strut spring, rotate the wheel at a decent speed. You should feel a vibration in the spring which is an indication of a bad wheel bearing.
I had a bad howling/vibration on my wife's Trailblazer that was caused by a bad wheel bearing, but didn't know which side was bad.
The only way I found which side was bad was by holding onto the strut spring.

 

Also I forgot to mention. It pulls slightly to the right but is not wearing the tires uneven. Maybe like it has some drag on the right side.

 

Sounds like either a bearing going out or your right side caliper is hanging up. Is there excessive heat from the right side after driving?

 

What is the best way to check the wheel bearing,caliper, and the 4wd actuator at the bearing.

 

Bearing: See above. Caliper: See above. Actuator: No idea

 

you sure your not hearing your IWE ...