Just driven back from Eastnor Castle and endured the most horrible humming sound from the bus. My ears are still ringing, and I couldn't hear the scooby over the noise. It was a road speed noise, not an engine speed noise. It didn't change when the clutch was engaged/disengaged. It came on at about 30, got deafening at 40, eased off a bit at 50 and I didn't really go any faster than that (thoughts of exploding bearings and wheels falling off caused me to keep my speed down!) The sound resonated throughout the bus, and the engine seemed to have to work harder to haul the bus around. I had a similar (but quieter) hum the other day when I took a trip to Wolverhampton and back, but as it behaved itself all the way to Eastnor, I didn't think anything more about it. It seemed to mostly go away around sharp left turns (but not completely) and wasn't even doing that by the time I got home. Is it rear wheel bearings? At the service this year I got told that they were probably on their way out, but passed the MOT?