I have a 2003 with 94,000 miles on it. well I am having a odd humming sound coming from what sounds like to be the passenger front. It changes in pitch as I drive faster and reaches its loudest around 40. I know it isn't my bearings they are all changed. it doesn't change with rpms and my tires tread isn't the issue because i had diff tires on it when it started. what i can explain the noise to be is like a computer fan running or running on large swamp tires. any suggesting. its driving me nuts!