I have a 1999 automatic and when I drive on the fwy I can hear the front wheels/axel loud. It sounds like I need to lube it and when I drive slow in the street I hear a faint squeeking. Could this be a differential problem or bearings?
Yes, it could be a differential problem, or bearings.
When was the last time you checked the level of the front differential oil?
Maybe you need to “lube it.”
Check for worn U-joints going from the front differential to the front hubs.
Tester
Thank you, I will have that checked 
Gracias I will check that too