Rear subframe/mount problem, cant do alignment

Discussion in 'Gen 3 Prius Main Forum' started by Danny black prius, Jul 28, 2025 at 1:07 PM.

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  1. Danny black prius

    Danny black prius Junior Member

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    Hi Guys
    I try to figure out what should be course of action in my case, I have Prius 3 japan version, front suspension 100% condition but there is quiet yet frustrating knocking coming from rear left, passenger side when driving on uneven road, and more road noise, front is quiet.

    When driving, car pull slightly to right when steering wheel is straight, when I brake, steering wheel is turning left, is not in centre, on flat road etc, not much but still is noticeable, I bought 2 new front tires and done alignment, front is perfect but I found that rear left is not straight on diagram(please see pic)
    [​IMG]

    My question is if I should change only subframe mounts, if that will fix rear alignment or if I should change whole subframe because is bented? I went to one mechanic but he didnt found any cracks on mounts but car have 108k miles at the moment, please let me know what you think about this.

    Regards
    Daniel
     
    #1 Danny black prius, Jul 28, 2025 at 1:07 PM
  2. Tombukt2

    Tombukt2 Senior Member

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    You need to look at where everything mounts in the back and take a pry bar and see if you can pry anything down that looks bolted up a lot of times those subframe inner threads become undone from frame of car and the stuff can bounce look at sway bar box and all that . Something is making that banging noise . I guess that yellow on lower right of diagram is showing thrust angles off not sure .
     
    #2 Tombukt2, Jul 28, 2025 at 1:50 PM
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  3. Danny black prius

    Danny black prius Junior Member

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    what means if thrust angle is 0.06?
     
    #3 Danny black prius, Jul 28, 2025 at 2:06 PM
    Last edited: Jul 28, 2025 at 2:16 PM
  4. Danny black prius

    Danny black prius Junior Member

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    what mean if thrust angle is 0.06?
     
    #4 Danny black prius, Jul 28, 2025 at 2:08 PM
    Last edited: Jul 28, 2025 at 2:15 PM
  5. Danny black prius

    Danny black prius Junior Member

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    that is front axle diagram
    upload_2025-7-28_19-14-39.png
     
    #5 Danny black prius, Jul 28, 2025 at 2:14 PM
  6. PriusCamper

    PriusCamper Senior Member

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    What's the history of the car? Has it ever been in an accident?
    Maybe previous owner had damage that didn't get properly repaired?
    Could it be that the frame was bent and needs to go to a body shop and pulled straight on a frame rack?
     
    #6 PriusCamper, Jul 28, 2025 at 2:49 PM
  7. Tombukt2

    Tombukt2 Senior Member

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    But your alignment is completely in the green?. So does car track true not braking of course? If so then I'd say what ever is clunking in back . Is causing the of kilter responses of the car . So I would think it would be something pretty important major structural membersb8n tear that are no longer structural or loose as in broken threaded holes etc . Mite oughta find.
     
    #7 Tombukt2, Jul 28, 2025 at 2:55 PM
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  8. Tombukt2

    Tombukt2 Senior Member

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    Do first diagram shown cambers off on left front it looks like usually arrow is front of car.
     
    #8 Tombukt2, Jul 28, 2025 at 2:58 PM
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  9. Danny black prius

    Danny black prius Junior Member

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    first diagram
    [​IMG]
    this is only rear axle, that yellow car symbol on bottom right is to indicate which axel is checked, yes its still green but just about, my car pulls only little bit as well, car drives straight when steering wheel is slightly to left, when drive straight and i keep steering wheel straight than car go to right but little bit, my plan is to change 2 rear subframe bushings but i dont know if that will change rear alignment
     
    #9 Danny black prius, Jul 28, 2025 at 3:05 PM
  10. Danny black prius

    Danny black prius Junior Member

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    I am not sure but I see that front right lamp is new, bonet was repainted, otherwise front suspension is quiet and everything looks ok
     
    #10 Danny black prius, Jul 28, 2025 at 3:08 PM
  11. bisco

    bisco cookie crumbler

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    any unusual tire wear?
     
    #11 bisco, Jul 28, 2025 at 8:43 PM
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