Noise on SUV: My 97 Ford Expedition, 51K miles, 2WD, seems to be making more
noise than a few months ago. It sounds like the RPM is too high, yet the
tach generally shows no more than 1K to 1.5K in any gear on a flat roads at
slight acceleration. It sounds like the automatic transmission shifts about
at 15 and 25 MPH. The noise seems to be directly proportional to road speed
rather than engine RPM. Sounds noisy even when 25 MPH and coasting in
neutral. Transmission fluid shows proper level. Tires are Goodyear Fortera -
18 months and 4K miles. I don’t remember the road noise being related to the
new tires. The sound is not high pitched as you would normally hear when
bearings go dry. Any ideas what could cause the noise?