Humming and vibration

So i got all of my wheel bearings replaced a little over a year ago. Everything has been fine up to now. I will be driving and a loud humming noise and vibration throughout my whole cab will happen but it will only last for about 5-10 seconds at a time and it happens randomly. It will occur maybe 3 or 4 times a week. i for sure know it’s not me driving over something in the road. any ideas of what it could be. maybe alignment issues? i don’t know if it would be alignment becuase i just got alignment done about 2 years ago.

 

Wheel balance? Sometimes a weight falls off and messes it all up.

 

Likely u joints, if they havent been changed its likely time, along with the carrier bearing.

Search up bad u joint posts and see if they match your symptoms.

To inspect them they are a pain, you typically have to remove the shaft.

 

This ^^^^^^^^^^^^^^^^^

 

So i figured out what it is. It is the Diff support mount bushing. I can move one side of the diff up and down which causes the drive shaft to move and the cv axle to move. Would these vibrations and movement cause my diff to fail or could it have already gone bad?

 

Obviously get that bushing fixed. Is it the drivers side or passenger?

 

it is the passenger side

 

It’s possible the movement in the diff could’ve caused the needle bearing wear that guys get when they lift their trucks. That needle bearing issue occurs on the drivers side, but I’d imagine the diff movement could bring it about. If the diff support bushing doesn’t fix the humming/vibration, try 4wd when it humms/vibrates and see if it stops
I’d definitely start with the bad diff support bushing first. I only mentioned the needle bearing cause that was my first thought when you said it comes and goes, before you identified the bad support bushing

 

Before i knew what it was i had it in 4wd and it seemed to make the vibrations more intense. I did buy this truck used on fb marketplace i’m pretty sure it has a aftermarket lift on it because i can see some spacers on the front suspension

 

I’d start with the support bushing, then reevaluate from the there. It’s possible the needle bearing needs replaced with the ECGS bushing, but you already know support bushing is bad