2008 Taco with humming noise that goes away with 4WD engaged

I've had this noise for a number of months and have noticed that when I engage 4WD it goes away. I replaced both front wheel bearings and hubs last month and had my front CVs replaced about 4 months ago. Truck has OME lift with dakars and the complete front coils assembled by Toytec with top plate spacers and Light Racing UCA. Tires are aired to spec and have about 40,000 miles on them so I have considered that it was road noise from them but again the sound disappears entirely with 4WD engaged. It is a much lower growl at slow speeds and as I go faster the pitch increases. I'm out of ideas to say the least. Thanks in advance for any help

 

needle bearing in the drivers side front diff?

 

sounds like the needle bearing. ECGS makes a replacement, that solves this. I havent done it, but many have. lots of info here on the site about it

 

annnnndddd this is why i love this site!! thank you! i will be looking into this option

 

https://www.tacomaworld.com/threads/ecgs-bushing-replacement-and-write-up-to-follow.472081/