1st gen Tacoma- Noise when in 4wd.

Greetings everybody!
I've got a 98 Tacoma 4wd with manual locking hubs, manual transmission....and there's a rumbling sound from somewhere towards the front. I tried only shifting into 4wd without the hubs locked in, and there's no noise. Then when I lock the hubs, in the noise comes back. It sounds almost like a badly dragging brake system, best I can describe it.

I knew you guys would be able to help me.

Thanks in advance!!

 

Have you checked your front CV shafts and front driveshaft ujoints for play or binding?

 

I haven't yet, this just started in the last couple days.