Unusual Noise from Drivetrain

[Blue)(Fusion]

Hello all,

I have found alot of useful information/tricks/suggestions on this site regarding my and my parent's car in the past few days. There is one problm that we have been trying to figure out for a few months now, however.

My dad has a 1999 Crown Victoria with the performance package (dual exhaust, traction control, air ride, etc.). A few months back he took it in to the delear and had a new transmission put in and his tires rotated. I'm not sure of the reason behind the tranny replacement as I was away at college. So whenever I drive with my dad in his car, I hear a noticable noise throughout the cabin. Since it seems to reverberate throughout the body of the car, it's hard to pinpoint where it's coming from. We figure it has to come from either the tires or the transmission.

The sound that is made is not affected by the engine RPMs, but directly related to speed. If the engine is idling or revved but at a stop, there is no sound. If the car is moving, say downhill and the throttle is idle, the sound pitch is in flux with the speed, from low speed to highway speed.

So I checked all 4 tires to see if the idiots at the dealership put them on incorrectly (they once were only hand-tightened so one nearly came flying off once). Everything was tight and facing the correct way. So it's unlikely it's related to the tires.

The transmission might be the culprit but I'm not certain how to check that. Is there any way to do a road test and see if it is the transmission or some other assembly on the drivetrain?

Does anybody have any ideas of what this can be? FWIW, there does not seem to be any unusual deceleration or drag imposed by this, just the noise.

[Stick462]

Try rotating your spair tire on all four corners first /it could be a bad tire?

[Blue)(Fusion]

Just to follow up. It ended up being a bad wheel bearing which was causing the noise. Thanks for the help though.