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Is this the sound of a bad wheel bearing or transmission ?

Discussion in 'Gen 2 Prius Main Forum' started by *Goldfinger*, Feb 26, 2024.

  1. *Goldfinger*

    *Goldfinger* Junior Member

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    Hi All,
    I'm getting a humming noise when I go over 45 mph (not getting any vibration through steering wheel). I've had the front tyres replaced and balanced but that didn't make any difference and the rears are both relatively recent and in good condition. It doesn't seem to change as I speed up and I'm struggling to identify where it's coming from. My 2007 Gen II has the original wheel bearings and has done 81k miles on the original transmission fluid.
    I was unable to upload mp3 files so below or links to the files in my shared Dropbox folder
    Your thoughts would be greatly appreciated.
    Thanks
    Goldfinger

    Dropbox - Prius hum 64mph mp3.mp3 - Simplify your life

    Dropbox - Prius hum 79mph m4a.m4a - Simplify your life
     
  2. justlee

    justlee Junior Member

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    Wheel bearings will change sound when weaving side to side if they are bad. For example if you have a bad bearing on the left side it will get louder when you turn right and maybe just a little more noisy than going straight when you turn to the left. Bad bearing in the transmission won't change with direction of turning.
     
  3. Tombukt2

    Tombukt2 Senior Member

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    At 81K I would hope not to have a bad wheel bearing or a bad transmission bearing. That is annoying now and almost sounds like a belt in the tire
     
  4. Aegean

    Aegean Active Member

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    First it is extremely unlikely to be a bad CVT. The bearing scenario is more likely especially if it comes from one of the 4 wheels.

    Get another person to drive, then seat on the back and identify where it is coming from. Climb as needed and turn your head until you identify where the noise is coming from
     
  5. Tombukt2

    Tombukt2 Senior Member

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    It's a generation 2 so just the year factor alone puts you in the realm of thinking about wheel bearings they're not that expensive I mean if you want to buy the factory original Toyota ones for 180 bucks a pop or whatever it is I say be my guest I'm running TRQs about $39 a pop got a few years on a couple of them pretty uneventful as fast as they are to change I'll pay the 39 to 50 bucks or something like that I am not paying $160 or whatever it is 139 180 no sir matter of fact I keep a set of hubs with new bearings bolted in them and new lower ball joints sitting in the corner of the shop for Gen 2 and Gen 3 which the Gen 3's I got to get rid of because we no longer partake so no need to hold on to those kinds of parts that way there when you're going to go change your struts or what have you You can just slide those new hub assemblies right up to your drive axles and drop them on the lower control arms and tighten up all the bolts and maybe 35 minutes aside No problem so just the fact that the cars you know almost 20 years old if it's a generation 2 just the amount of years you're there to heck with what the mileage is it should be over 100,000 but just because it's 89K and right at 20 years old just the age factor alone makes sense to be looking at the wheel bearings and struts and things that your kidneys and rear end will feel.
     
  6. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Wheel bearings can be ventriloquists. Tough to spot the noisy one(s) with road testing only, much better to lift the car and spin the wheels by hand while listening for that clickety-tickety signature.

    For the toughest cases you use a set of Chassis Ears (name of the tool) combined with a test drive. Not all shops have that toolkit.

    I agree with Aegean that bad transaxle is very unlikely. Meanwhile we've already had one wheel bearing go bad in our car, less than 75k miles at that time.
     
  7. *Goldfinger*

    *Goldfinger* Junior Member

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    Thank you all for your comments and advice, much appreciated
     
  8. *Goldfinger*

    *Goldfinger* Junior Member

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    Update - It turned out to be both front wheel bearings. A fairly easy job to replace apart from getting the bearing housing out of the steering knuckle (they get corroded in) both mine needed a 5 ton press to budge them