Rattles at 40 mph? Sounds like the point where the torque converter lockup clutch engages. Not enough information about the noise and any vibration felt, if it occurs only when you reach that speed and then disappears or the noise is constant after your reach that speed. Usually you will hear and/or feel a slight clunk when the lockup clutch engages when you reach a certain speed or after using the passing gear.
2002 Almond Pearl Limited Edition 27K
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