A whining noise heard driving at freeway speeds (more than 55 mph) can be normal noise from the rear axle which is being transmitted through the body. A body/frame damper is available which may help with this concern.Google+
Car Problem Reports
Chrysler Aspen Whining Noise at Freeway Speeds May Come From Rear Axle
Chrysler Aspen Problem
Drive Trains Affected: 2WD, 4WD
Average Mileage: 63,400 mi (12,000 mi - 143,000 mi)
Above 60mph a varying whiny noise can be heard ... not at lower speeds. The tone varies slightly depending on summer or winter tires. Dealer has suggested a rear differential rebuild.
Visitor, 2008 Chrysler Aspen, 2WD, 40,000 mi
Whining/humming sound at 45 mph up to about 65 mph when gas pedal is pressed. When coasting, the sound goes away. Having the pinion gear in the differential replaced, which supposedly will fix the problem, or so the Chrysler dealer tells me...glad it's under warranty.
Visitor, 2007 Chrysler Aspen, 2WD, 12,000 mi
whining noise at 60 mph
Fixed with new rear end