Chrysler Repair: trans makes buzzing sound, dodge carivan, solenoid switch

Question
I have a 2000 dodge carivan. the trans has a buzzing sound in all gears.  no codes, drives fine shifts fine.  buzzes in nuteral and park. louder with rpms.  does not make the noise for ten minutes after start up.

Answer
Hi Mike,
Check the fluid level in the trans. See if it looks aerated after it begin buzzing (bubbles).
Use a length of rubber hose with its tip in your ear to attempt to localize the source of the buzz (like a stethiscope). If it is from the torque converter (in the bell housing just behind the engine then it might be a mechanical rubbing of the converter on one of the covers, otherwise it is a sign that the converter is failing). If it coming from further back on the transmission then you might see if it is localized to the box on the side of the trans that faces the front of van. If so, then that va;ve body/solenoid box should be checked for a failing solenoid switch or other electrical component within. If that proves OK then it could be a part wearing in the trans proper which would be shown by debris found in the pans when "dropped" for maintenance/fluid change. The inner race of the overrunning clutch is one suspect.
Those are the major possibilities, but localizing the source is probably the best first step. Then take it to an independent trans shop for further diagnosis. If you can circumvent the need for a rebuild it would be worthwhile.
Roland