1998 Legacy Brighton, 5 spd, 173,000 mi.
This problem started suddenly a few months ago at the beginning of an 800 mile trip. I took the car in upon returning, and the Midas shop found some fuel injection and spark plug problems in the engine. $600, and the sound returned as soon as I drove away. I took it back, and they found that both rear tires had broken bands. $200 and the sound got better, but still didn’t go away.
The best way to describe it is a howling. It starts at ~40mph, and depending on the day will get significantly worse at 55mph, 68mph, or 72 mph. The sound comes from the rear of the car, from near the rear driver’s side wheel.
I had one shop tell me it was my left rear wheel bearing, but that he couldn’t do the replacement. Another shop said they could do the replacement, but the bearing in that wheel was fine. They suggested that the sound might be coming from the differential.
Any thoughts? Other than the noise, the car runs and drives beautifully. No grinding, no roughness. Just a slight shudder when braking down past 40 mph.
Yes, it could be a wheel bearing, and if it is, the fact that the noise has been present for a few months indicates that you may be at a crisis stage with the bearing. Trust me–you don’t want to be driving at high speed when a wheel bearing seizes. Having one wheel “locked” by a seized bearing would make it very difficult to control the car and it is conceivable that an accident could result from that situation.
It could also be the differential, and while this may not be as dangerous, it has the potential to be very expensive if allowed to continue. So, I would suggest that you take your car to a competent independent mechanic–NOT Midas, or Meineke, or Monro, or Sears, or any other chain operation–and have this situation resolved a.s.a.p. before you regret allowing this to continue for several months.
Has anyone checked the differential oil level?