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Broken Lug Stud

Discussion in 'Prime Care, Maintenance and Troubleshooting' started by minimalist, Apr 28, 2020.

  1. minimalist

    minimalist New Member

    Joined:
    Sep 17, 2019
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    Location:
    Ontario, Canada
    Vehicle:
    2018 Prius Prime
    Model:
    Base
    Unfortunately I broke a drivers side rear lug stud recently while re-torquing my wheels on my 18 Prime Base. I was using a torque wrench but must not have been using it correctly. I noticed that some nuts would no longer turn when the torque wrench clicked. This, I thought was the ideal tightness=goal. Other nuts would turn a little then click. So I kept tightening the nuts in a star pattern when a lug stud broke.

    I would like to attempt to replace the lug stud on my own but have never done this fix.

    I see some guides online but have a few questions:

    1. Is it necessary to remove the brake caliper and rotor?

    2. If yes, I understand that I need to disable the ABS system. How is this done? Is it sufficient to detach the 12V battery's negative side only or do I also have to remove the ABS fuses?

    I'll try to use a C clamp to push the broken lug stud out. I don't want to hammer on it as advised online.

    Any tips will be appreciated!
     
    #1 minimalist, Apr 28, 2020
    Last edited: Apr 28, 2020
  2. jerrymildred

    jerrymildred Senior Member

    Joined:
    Oct 28, 2016
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    Location:
    Tampa, FL
    Vehicle:
    2017 Prius
    Model:
    Two
    Let me see if I can wake up this thread. I'm surprised one of our brake enthusiasts hasn't noticed it.

    If you haven't already gotten it, yes, you will need to remove the brake rotor. Disconnecting the 12V battery will suffice to keep the car from doing squirrelly stuff with the brake pad pistons.

    You might get it out using a large C-clamp to push the lug into a large enough socket. If not, you'll need a hydraulic press. You are wise to not hammer on it.
     
    #2 jerrymildred, May 6, 2020
    Salamander_King likes this.
  3. PianoBench

    PianoBench Member

    Joined:
    Mar 20, 2017
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    Location:
    San Francisco
    Vehicle:
    2017 Prius Prime
    Model:
    Plug-in Advanced
    I think you can just buy the entire driver side rear (LH) hub. Have a look at the link below for the diagram and part numbers. The part number is 42450-76020

    Genuine Rear Axle Shaft & Hub OEM parts for the Toyota - Prius PHV - ZVW52 - A PREMIUM TYPE - 2ZRFXE - 2018 supplied from Japan - Nengun Performance

    I've seen someone replace and add a bolt onto an existing stud hub, but I don't recommend doing that. I think it is easier and safer to replace the whole thing.

    See this video on how to replace the hub. It isn't the exact steps but it should get you close enough.


    Here is the exact steps for an older model Prius. The rear stud hub looks very similar to the part I linked above.
     
    #3 PianoBench, May 14, 2020
  4. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
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    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Was this a new torque wrench for you? were you using the spec'd 76 foot/pound setting?

    Just in case you don't know: for taking rotors off, there are two tapped holes in the rotor center portion, 180 degrees apart, that you can screw in M8X1.25 bolts (say at least an inch long). Just keep screwing them in, a half-turn at a time, one then then the other. If there's a lot of rust you may need to back them them out, blow out the rust, then repeat. Eventually it'll pop free.
     
    #4 Mendel Leisk, May 14, 2020
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