1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Getting a click-click-click noise under braking? I found the culprit.

Discussion in 'Gen 3 Prius Technical Discussion' started by E46Prius, Dec 22, 2020.

  1. E46Prius

    E46Prius Active Member

    Joined:
    Aug 3, 2015
    314
    218
    0
    Location:
    Costa Mesa
    Vehicle:
    2015 Prius
    Model:
    Three
    My 2015 Lexus CT200h F Sport developed a clicking noise under light load braking coming to a stop around 20-0mph. Coming from the driver's side wheel area. The noise started at around 40,000 miles. I now have 58,500 miles. You could hear the noise from inside the cabin, with the radio off. Just a tick tick tick tick that synced with the car's speed. Yes it's a different car, but the Prius shares the same driveline components. So I thought I'd help you all with this post.

    This noise drove me crazy. I pulled the wheel and triple check everything is torqued down and tested for play where I could. I tore down all the individual brake components, shims, pads, cleaned, relubed, retorqued. Nada. No change.

    I always suspected the driver's side axle was somehow to blame, but didn't see any tears, leaks, play, or any other abnormality.

    So I finally decided to come up with a gameplan. I bought a CV joint boot kit, some Timken axle grease, and special CV joint pliers. I repacked the bearing as best I could with new grease (left the axle in place) and voila--the noise is gone. I tested it 4x to be sure, 4 different drive sessions getting the car nice and hot. I do note the stock grease was gray and kind of runny, not as thick as the new grease. The axle was not leaking grease and did not seem to be low on grease, the car just seemed to not be happy with the quality of the grease.

    Now while I get no noise while driving straight and braking, if I brake lightly while turning and coming to a stop, the noise comes back but is faint. But I'm happy that it doesn't do it while going straight which is 99% of my situation. I may revisit and try to pack it with more grease or may just leave it alone. But the grease clearly 100% made a difference.

    The way I finally confirmed it was the axle is that while braking and the clicking/ticking was going on, I would put the car in neutral which takes load off the drive train--immediately the clicking ceases.

    Hope this helps someone.
     
    ppongi and Soh like this.
  2. Grit

    Grit Senior Member

    Joined:
    Aug 22, 2017
    6,103
    4,032
    1
    Location:
    Wilkes Land
    Vehicle:
    2012 Prius
    Model:
    Four
    Great post. Other members had the same results as welll. Some reported back that some thousand miles later, the clicking came back which the new cv part started doing it also.
     
  3. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,463
    38,101
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    How do those replacement boots work; they have a split?
     
  4. E46Prius

    E46Prius Active Member

    Joined:
    Aug 3, 2015
    314
    218
    0
    Location:
    Costa Mesa
    Vehicle:
    2015 Prius
    Model:
    Three
    I didn't replace the boot, just the grease and new clamps. The old clamp pops off by prying with a screw driver and the new clamps get wrapped around the axle, then pinched on tightly. the pinch part is low profile as to not interfere with the balance of the axle as it spins. you'll want to avoid the ones with the screws you turn as those screws are heavy and sit up high which can cause vibrations.

    The noise is still gone and axle is quiet.

    That's discouraging to hear others have had the sound come back... i guess it's "normal"?

    Do aftermarket axles do this too? I guess if the sound comes back i'll just live with it. i really don't want to be messing with cars... the whole reason why I got out of the BMW scene (as fun as it was) i hated wrenching on cars constantly to maintain them. i just want to drive into my sunset years with minimal fuss LOL
     
  5. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
    11,490
    14,095
    0
    Location:
    Tampa, FL
    Vehicle:
    2017 Prius
    Model:
    Two
    Interesting that thicker grease made a positive impact. The shop looked at my wife's car and couldn't find anything amiss. (Mine makes the same noise, but I chose to take hers in.) They finally drove a brand new one and it made the same noise. But obviously not all new ones do that. Very strange!! But I don't think it's harmful.

    My theory at the moment is that some (many?) greases, if they are on flat surfaces that get pulled apart make kind of a lip-smacking noise, which will sound like a click. It may be that some viscosities are more prone to that noise and some not so much.

    Anyway, keep us posted on whether the noise comes back. Whether it's harmful or not, it is a little annoying.