One problem related to power train driveline has been reported for the 2004 Toyota 4Runner. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Toyota 4Runner based on all problems reported for the 2004 4Runner.
I own an 2004 Toyota 4runner sport with the v8/awd. Took it on a long road trip over x-mas and noticed at exactly 71mph you start to hear a cyclical noise (about 2-3 per second) that increases in frequency as vehicle speed climbs. No vibration in steering wheel or pedals. But both driver and passenger feel it in floorboards and hear it. Disappears at 82 - 85 or so, and as soon as foot is removed from the gas pedal. Dealer claims no known issues and offers no solution.