Most of the time a speed consistant squeal is a driveline issue.... if you can hear it mainly under the console, it could be a lack of grease in the double cardan joint of the front drive shaft and/or bad ujoint(s). Don't rule out a hub bearing or the rear ujoints... sound travels funny under a rig.
Try to isolate it first by taking off the front shaft and drive it... if it goes away completely.... you have found the culprit.
~Todd~ 2004 X 4.0 5 speed---SOLD
4" Lift, 4.56's, 33" Duratracs on M/T Classics
RR SYE, Tatton CV, MML, BL, TT, Dynomax Exhaust
Hella Lighting: Driving, Fogs and H4 E-Codes
... and NEVER will be