Drive Line noise

1995 XC 3.4L 5 speed 4X4 ~ 180,000 miles. I have a noise/vibration in the drive line somewhere. I say it is in the drive line because it occurs regardless of engine speed, whether the clutch is engaged or not, whether the trans is in gear or in neutral. This is not a new noise. Been there as long as I have owned it. Has not gotten any worse in over 20,000 miles. Only noticeable at very low speed. It seems to be related to wheel rotation speed, as in if you let off the gas and let the truck slow down, or push in the clutch & let it coast to a stop, the frequency gets slower as the truck gets slower. The sound is not very loud. Normal conversation would cover it. It is almost like a rumble. Not metallic. Similar to the noise an unevenly worn tire might make. Not enough to"shake" anything, but I can "feel" it. Any suggestions? I would post a video but it is not loud enough to record. TIA Stan.

 

Universal joints or carrier bearing?

 

Not as far as I can tell. They all seem good.

 

Also, forgot to mention, the noise is present in 2 or 4 wheel drive, is not intermittent. Tires are new w/ <1,000 miles.

 

Can you tell whether it is coming from the rear or front?

Other ideas:
- sticking front caliper
- slightly warped front rotor
- slightly warped rear drum

 

Sounds like more towards the front.

 

Could be your brake dust shield rubbing the wheel. Pull/bend it back and away from the wheel.

If it was coming from the rear I'd suggest checking the spare tire mount... I have seen a loose tire/mount chirp and make noises.

 

I don't think it is the dust shield-not metallic sounding at all, but I will check that out. Spare tire mount does make some noise when hitting bumps/potholes(lots of those in this town) but not associated with this.

 

Jack a front wheel up off the ground, and spin it. See if it makes the noise. Then do the other side.

 

Second this ^^

It could be a bearing(s). Is there any change to the sound when you go around a corner?