Hard to say. How many miles on it? Have you change ATF on it? Have you checked to see how the ATF looks? I believe 2004 falls within the range of years the ATF cooler fails internally, allowing coolant and ATF to mix, which trashes the transmission.
These old school Jatco 5spds are generally very reliable units.
These old school Jatco 5spds are generally very reliable units.