Can someone help out? I have a 2002 SuperCrew 4x4 that makes a squealing sound that starts at 3000 rpm and slowly goes away as it approaches 4000 rpm. It does this when you are in park or in gear. I believe the torque converter is going bad, but just want to make sure before I tear it all down.
Can anyone give insite on this?

 

Kinda doubt the TC is the Issue...the TC shouldn't be in play when in Park. NOT that can't be, just way farther down the list.

I would sooner suspect a idler or the tensioner or some driven component of the serpentine belt.

Remove the serpentine belt and start it (briefly) and rev it to that troublesome RPM range and see if it goes away. If it does then you narrowed it down substantially to a item driven by the belt.

From there, With engine off, hand spin each component and see they feel rough, might have to get a long screwdriver or mechanics stethoscope and listen for a growl , you might have a bearing showing its age. It maybe that the tensioner is loosing it ability to keep the belt tight or the belt could need replacing.