Howling/Vibration while driving, help!

Hey, Y'all! I need some help. I have a 2004 Tacoma 4x4 TRD, and i'm experiencing some vibration/howling when I drive. It FEELS like its coming from the front, but I haven't had any luck diagnosing it. Let me know if you have any suggestions!

I notice the howling/vibrations from 30mph+ and its VERY noticeable at around 70mph. It happens while accelerating/decelerating, as well as while breaking. I assume that it's something associated with the movement of the vehicle because it becomes more prominent/less prominent with the speed that I am traveling.

I bought new BFG KO2 tires and had it aligned about a month or so ago, so it shouldn't be from uneven tire wear or poor alignment. I have looked through some threads, but vibration can come from so many different things, its hard to get an idea of where to start. I do have a torn CV boot on my front right side, but I don't hear or feel any clicking while turning, but could that be it? I also don't know if the U Joints in my drive shafts have gone bad, but could there be play and movement due to the centripetal force from the spinning of the shaft, thus causing the vibration/howling as I go faster/slower? Lastly, I had my oil changed today, and the technicians told me that my rear diff fluid was pretty dirty. I know a howling sound can come from a lack of/or dirty fluid that comes from within the rear diff, but what do y'all think? And what path would you take to diagnose or figure it out?

I wan't to avoid taking it to Toyota as long as I can because last time I went to them I had to pay $150 for diagnostic charge for a delayed/intermittent starting problem, and they said they couldn't find anything. Still have to figure that issue out too.. :/

I appreciate any advice that you might have!

 

For the intermittent problem, check all your ground cables. Battery to frame, to block, to cab and so forth. They need to be snug and clean. For the howling noise, the carrier bearing can do that. That an easy check, you might be able to move it back and forth by hand just a hair. I'm not much of a 4 wheeler so good luck if the noise is coming from that.

 

I appreciate the reply! I will check out the carrier bearing and keep you posted. When I brought the truck to Toyota for the intermittent/extended crank issue, they said they checked the battery, the plugs, etc. I'll have to find the locations for all the ground wires to make sure they are good to go. Some people who had the same problem said that they had leaking fuel injectors. I am praying to the good lord above that's not the case haha. The truck always starts, ive never had to turn the key more than 3 times, but we will see!

Thank you again for the reply!