Humming Sound at High Speed

A low humming or buzzing sound becomes audible when my Prius is going faster than about 40mph. The noise is there regardless of whether I’m coasting or have my foot on the gas, and it appears to increase with speed. It doesn’t sound too different from the noise of the transmission when in B mode (engine brake) mode, though it remains when in D. Not super clear where it’s coming from...I thought it was from the back left but a passenger recently said it sounded more to the right.

Tire pressure is normal.

Any ideas what it could be, and how to check?

The car is a 2010 Prius with 160k miles. I’ve had it for two years and only noticed the noise this summer.

Thanks!

 

Yeah, mechanic said it’s rear right wheel bearing. Looks like a pretty feasible DIY job. how much difference does the brand make - OEM vs Moog or Duralast?

Thanks!

 

Finally got around to changing the rear wheel bearings. It was pretty straightforward using the 1AAuto video, but the old hub assembly was rusted onto the dust cover with the tenacity of 10 years and 160k miles. It’s hard to overstate how stuck that thing was...Forget pry bars, slide hammers, mallets, etc.

Instead, buy a handful of 5/8” by 4”-long bolts with hex heads, a washer and two nuts for each bolt. Assemble as in the photo and work the hub assembly off the dust plate using a socket wrench on the bolt head and a wrench on the nut that’s closest to the washer (twist the nut, not the bolt head).

This method was far quicker and easier than anything else.

 

FYI, about 600 miles after what was an apparently successful pair of wheel-bearing replacements, my braking system went haywire. ABS, slip-indicator and brake-system lights all turned on, regenerative braking gone, deceleration only achieved by pressing firmly down on the brake pedal.

do not know if the two things might be related.

See thread:

ABS, slip, brake system warning lights | PriusChat