One problem related to transmission noise 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.
My 2004 Toyota v8 4wd sr5 4runner was bought brand new in Feb/2004. At speed 71-73 mph, it generates annoying harmonic humming noise from transmission and/or driveline. The noise is more noticeable in cold weather than in hot one. It become less noticeable at speed above 78 mph. A Toyota dealer mechanic test drove the car and confirmed the noise, but offered no help to fix the problem because they do not know how to.