I just bought my first Landcruiser and so far I love it. The only problem with it is a slight vibration / roaring type noise that is loudest at about 40 MPH. When I let my foot off the gas and take torque off the wheels, it immediately goes away. It is not the engine and I suspect it is the universal joint(s). Has anyone had similar problems or have suggestions on how to test?

could be a number of things, tires, driveline play. How many miles?