This article is from the Chrysler-Plymouth-Dodge FAQ, by Dr. David Zatz with numerous contributions by others.
Jim Zimmerman said TSB 21-40-93, affecting most FWD vehicles from 1989
to 1994, covers this. This noise comes from the transmission of the
FWD cars and minivans, with automatic "transaxles built with 3.02 or
3.22 final drive gear ratios. 1994 model year vehicles must have a
transaxle code prior to 1826 for this bulletin to apply." This is a 7
hour job and replaces MANY parts.