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Is this the cause of all the humming road noise?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Karadoesntkara, Jun 10, 2020.

  1. Karadoesntkara

    Karadoesntkara New Member

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    I've had a humming noise that seems to get louder the faster I drive for a few months now. I thought it was due to my tires being so worn, but I had all four replaced, rebalanced and an alignment done (minor misalignment) and the noise is still happening. It sounds like those big Jeep tires haha. I believe the passenger side wheel bearing was replaced a few years ago, but the sound is different and does not change much when I turn the wheel. This is a loud hum and not crunch or squeal like the bearing was. I don't know too much about cars, but noticed the passenger side CV joint? seems off. I also noticed some fluid leaking by parking break which may/may not be related? Most of he posts I've read points to the humming as the bearing but this is a totally different sound than last, so I don't suspect it is the same issue. Any ideas?

    Oh this is for a 2008 Prius with 212,000 miles, its a trooper! :D
     

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  2. Geoffzie

    Geoffzie New Member

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    I know this is an older thread but ... I'm having the same problem ... Road noise in the front. I've already looked through all the "road noise" threads here.

    Did you ever find your problem?
     
  3. bisco

    bisco cookie crumbler

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    if you've changed the tires, it's probably a bearing or cv joint
     
  4. Geoffzie

    Geoffzie New Member

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    I already replaced the wheel bearing ... But still had the road noise afterwards, even with different BF Goodrich M&S tires! I also inspected all the front-end components, including the CV joints and boots ... All looks good.

    I'm going to put the front tires on the back, and the backs on the front ... If the noise moves, I'll know it was the tires ... If the front STILL makes noise, I'll know it's NOT the tires.
     
  5. Geoffzie

    Geoffzie New Member

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    Ok, today I put the front tires on the back ... And the back tires on the front ... STILL have the same noise in the front, so it's NOT the tires!

    I also put the front up on jack stands, turned the car on, and put it in drive ... As the wheels were slowly spinning, there was no noise on the driver's side (where I replaced the wheel bearing) ... But there DOES seem to be rotating noise coming from the passenger's side front.

    Quite possible I changed the WRONG side wheel bearing!? Sure sounded like the driver's side when driving ... I should have had someone else drive while I sat in the passenger's seat!

    I'll have to get into it next week, to determine if it's the passenger's wheel bearing, or CV joint.
     
  6. Geoffzie

    Geoffzie New Member

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    Finally got around to finishing this project ... It WAS the passenger's side wheel bearing ... And the outer CV joint was bad too. Replaced both the wheel bearing and passenger's side axle ... All is good now. There's not really any excessive noise from the Michelin tires. I was surprised that the axle CV joint was bad ... Since the CV boots looked in perfect shape!

    The moral of the story ... Make SURE which side the noise is coming from ... BEFORE you tear into things!

    And ounce of research and inspection ... Can save a TON of work!
     
  7. ChapmanF

    ChapmanF Senior Member

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    +100

    You can see from my old how to tell which wheel bearing? thread that sometimes it's really hard. All the different rules of thumb people usually suggest were falling flat, and I had to go get my hands on a ChassisEar before I could actually be sure which bearing it was.

    On the bright side, once the ChassisEar was hooked up, picking out the bad bearing took like three seconds.
     
  8. Geoffzie

    Geoffzie New Member

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    Thanks for that link ChapmanF!

    Although it's probably not a recommended practice ... When I placed the front of the car on jack stands, and started it up, and put it in drive ... Then put my ear to both front wheels ...It was abundantly clear which wheel it was!

    Rear wheels (on FWD) are much easier to diagnose ... since you can "feel" a bad bearing when you turn it by hand (without the wheel / tire).

    For the life of me I can't understand why manufacturers don't use Timken roller bearings ... Instead of ball bearings! (probably because of rolling friction and gas mileage?) I remember in the 1950's, when VW beetles first came to the states ... Front (ball) wheel bearings were ALWAYS going bad ... Until VW switched to roller bearings in the 60's.

    Seems ALL cars now-a-days have issues with bad wheel bearings!
     
  9. mr_guy_mann

    mr_guy_mann Senior Member

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    SOME cars have always had problems with wheel bearings. Perhaps it's more noticeable as cars are lasting longer and racking up 150k, 200k, and more.

    Yes, I would think that rolling efficiency is a factor in choosing ball vs roller bearing type.

    However, there's more to longevity than type. Subaru has had problems with rear wheel bearings for something like 20 years. At some point (mid 2000's?) they tried to "fix" the design by going to a double tapered roller assembly. That didn't work. They aren't Timkens, but Koyo or NSK aren't bad when it comes to bearings.

    I do general automotive repairs and maybe 10% of my client base is Subaru, but over 50% of my wheel bearing replacements is Subaru rear bearings- which are all now tapered design.

    Posted via the PriusChat mobile app.
     
  10. Geoffzie

    Geoffzie New Member

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    mr_guy_mann ... Yea, I noticed that if you purchase Prius TIMKEN front wheel bearings from Rock Auto ... Their images actually show that they're KOYO bearings! ...
    Timken Bearing 2.jpg
     
  11. ammdb

    ammdb Active Member

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    That's the sound my rear hubs were making before I replaced with new hubs last month.
     
  12. Tombukt2

    Tombukt2 Senior Member

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    I grabbed two lower control arms aluminum part off a Gen 2 and I smacked in a new set of timken bearings and ball joints and then I put those on the car and I took the ones off the car and redid those and keep them on the shelf for the next gen 2 I have to mess with like that I did the same for my gen 3 I just have an extra set of control alarms it's just easier to have them out and ready to go and then trying to do it all at once when you have a few cars it seems to be easier

    SM-A715F ?