I've had a "growling" noise since late spring/early summer in the wife's '03 Mountaineer (4.6, AWD). When I did front brakes in June, I noticed the left-front inner CV joint boot was torn and leaking grease, so I ass-umed that was the noise source. The noise has progressively gotten worse since then. Today my father-in-law and I replaced the left-front CV shaft, again ass-uming the CV joint was the noise source. Take a wild guess what the post-replacement test-drive revealed... yep, same noise. $60 and 3 hours wasted - ooops. I've searched and read several threads on this subject, specifically how a rear bearing problem can act like a front bearing problem. BUT... given my symptoms, I'm still kinda stumped. Sooo, I'm gonna list what the symptoms are, and then what we've done... The symptoms: - "growling" noise and "feel" that varies with vehicle speed; started late spring and has progressively gotten worse since then - noise is present when going straight - gets significantly louder in right turns/curves, and kinda lessens in left turns/curves (but is still there) - can be felt in steering wheel in right turns/curves - does NOT change with braking or acceleration (straight or turn/curve) - noise is most noticeable in the driver's seat, and can barely be heard in the 3rd row seat/cargo area What we've done: - replaced LF CV shaft - checked LF and LR wheel bearings for play (grab top & bottom of tire and shake, grab L & R "sides" of tire and shake) - no play noted - jacked up left side and ran up to 15-20mph; could not hear anything from front or rear to pinpoint a source - rotated rear tires due to an odd wear pattern on LR tire It goes without saying that I can't afford to "troubleshoot by replacement", so any help you can give is appreciated.