I've always known that water in the transmission fluid is bad, but I didn't think it was the sort of thing that would cause fires. But that's exactly the reason that Chrysler is recalling about 240,000 Jeep Grand Cherokees equipped with the 3.7 L V6. The moisture condensed in the A/C evaporator does not drain properly, and can end up in the transmission sump. Eventually, the shuddering created by the fluid contamination can cause sufficient heat to be generated to boil the water out of the fluid, which then causes an overflow at the dipstick. The transmission fluid then leaks onto the exhaust system and starts a fire. Whew - that's quite the chain of events for a small drain tube to initiate.