Rear Axle Beam Assembly Replacement Complications

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by iconsult, Nov 22, 2008.

  1. iconsult

    iconsult New Member

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    All,

    I bought a used 2005 Prius (44k miles) roughly 2 months ago from a non-Toyota new/used car dealer. The dealer seems to have a good reputation in the area. It turns out that the rear axle beam was bent and that the car was probably in an unreported accident before they acquired the vehicle. The issue could not be identified until checking the alignment. I also had the issue checked with a good local auto body shop. It seems that the dealership either checked the alignment and sold the car knowing there was an issue or they never checked the alignment before selling it.

    I took the issue in to the dealer that I bought the car from. They replaced the axle beam with a USED part/assembly (~$1,250 worth of assembly and labor that they covered) and the problem seems to be fixed. They were accommodating in what could have been a challenging situation. I had the alignment checked with a 3rd party that fine-tuned the alignment and the issue seems to be resolved.

    Last night, the first night I drove the car since the repair, the warning light for the auto-leveling headlights came on. After conducting some research, it would appear that the sensor for the headlight auto-leveling feature is attached to the rear axle that was replaced.

    Note: The dealership that intended to fix the rear axle used a USED rear axle assembly that may have been sitting in an unprotected storage yard for some time. I believe that the dealership may have used the used (now possibly corroded) sensor from the replacement axle beam assembly.

    I have contacted the dealership and explained the situation in an attempt to ensure that they did not throw out the previously functioning sensor assembly yet (they did not). They intend to rectify the issue tied to the auto-leveling warning light (presumably the sensor) this upcoming week.

    Questions 1 & 2 - Replacing (swapping) the sensor seems to be a straightforward process. I've printed out instructions for them from this site. I am concerned that they will not know how to recalibrate the headlight aim (if necessary), however.

    1) Should I be concerned?

    2) Should I have the recalibration done only by a Toyota dealership?

    They strike me as a competent auto repair shop affiliated with many new and used cars (including two completely different major makes), though they are not familiar with the Prius (a unique beast in many ways) and they are not a Toyota dealership

    Questions 3 & 4 - I am concerned there are other possible sensors, parts or assemblies that may have been replaced / damaged when they swapped out some undetermined portion of the axle beam assembly (including subassembly items that were fully functional before).

    3) What else can be an issue that I am not yet aware of?

    4) Like the auto-leveling sensor, what other sensors, parts and/or assemblies are connected to or related to the typical axle beam assembly that could have been damaged or inadvertently replaced?

    Your insight is most appreciated.

    Rich
     
    #1 iconsult, Nov 22, 2008
  2. hobbit

    hobbit Senior Member

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    Krousdb managed to open his up and clean out the corrosion.
    .
    _H*
     
    #2 hobbit, Nov 22, 2008
  3. iconsult

    iconsult New Member

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    Hobbit,

    Thank you. I printed out instructions related to this. They are quite helpful.

    I am still curious if there are any other assemblies or parts (possibly sensors) that would typically be associated with the axle beam that I should be aware of. These would be something of an analogous nature to the headlight auto leveling sensor that is also located adjacent to the rear axle beam. I don't want to be caught by surprise regarding something else that this non-Toyota dealer may have missed (aside from the auto leveling sensor) when they installed the used replacement axle beam assembly.

    Again, thank you and thank you to the forum as a whole for the wealth of information on Priuschat.

    Regards,

    Rich
     
    #3 iconsult, Nov 22, 2008
  4. dogfriend

    dogfriend Human - Animal Hybrid

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    Other than the sensor for the auto leveling HID headlights, I'm not really aware of any other sensors or devices that you should be worried about. The only other sensors that I'm aware of are the ABS/skid control sensors that are built into the rear hub assemblies. If you had a problem with those, it should throw an ABS code and light up some of the warning lights on the dash.

    There is an anti sway bar that resides inside the u-shaped axle beam. You may want to check that it was installed if you are concerned about it. You can see it from the rear of the car.

    The only other concern that I would have is to make sure that the rear alignment is within spec after the replacement of the beam, which it sounds like you have already verified.
     

    Attached Files:

    #4 dogfriend, Nov 22, 2008
  5. iconsult

    iconsult New Member

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    Dogfriend,

    Thank you. Your insight is quite helpful and appreciated.

    No ABS warnings have popped up, fortunately. Unfortunately, the auto leveling sensor issue has become sporadic. My guess is that the sensor is indeed starting to go bad. I may try to repair it at some point if it acts up some more. The [non-Toyota] dealer that I purchased the car from indicated that they did not change sensors when they replaced the axle beam. Degradation, presumably corrosion, of an original 2005 sensor appears to be the issue.

    Thank you again.

    Regards,

    Rich
     
    #5 iconsult, Nov 24, 2008
  6. butchbs1985

    butchbs1985 Taking things apart is fun!

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    I don't mean to hijack this thread but I have been looking around for this kind of information. I was involved in an accident on the rear of my Prius. I had not had my alignment checked prior to the accident and did not have it checked immediately after the repair either. My favorite tire shop checked the alignment and told me that the rear was off (sorry but I don't have the printout). The said that they were not confident that they could align it properly so I took it to a Toyota dealer.

    The dealer said that the got it as close to perfect as it could be. The person who I was dealing with said "it appears that the rear cross bar is bent and that it will flex slightly causing the alignment to change". The cross bar does have a slightly upward curve but it looks just like the picture posted by dogfriend.

    I am going to be getting my alignment checked again soon and would like to more familiar with how it works. My questions:

    1. Is the dealers quote accurate?
    2. Even if it is bent, is there any reason that the dealer or service shop couldn't use shims to correct it? I can't imagine that the bar would flex that much. (Other than the self adjustment feature).
    3. How can I check to determine if the bar is bent? As I said, it looks good to me.
    - If it is bent, is it something I could replace given the parts? It doesn't look difficult compared to other things I've done.

    Thanks for your help!
     
    #6 butchbs1985, Nov 24, 2008
  7. dogfriend

    dogfriend Human - Animal Hybrid

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    Does that mean that it is within spec? It should be within the spec for toe in and camber as given by the Toyota service manual. Otherwise you should get it corrected to avoid accelerated tire wear and/or unusual handling characteristics.


    The axle beam will flex as part of the function of the suspension, but the alignment should be checked using standard conditions (given in the service manual) to get a repeatable static alignment. The Toyota engineers have taken into account the flex of the suspension in determining the alignment spec.


    If I understand what the dealer was trying to imply (that the alignment doesn't need to be within spec because it will change during operation) then I would say the dealer person either does not understand the purpose of alignment or is being dishonest.

    I corrected the toe in on my right rear axle using shims. It is not a procedure that is documented in the service manual though. There is an aftermarket shim now available to correct toe and/or camber (there wasn't when I shimmed my axle).

    I think the only way to tell if the axle beam was actually bent would be to compare it to another unit. It would be difficult to tell while it was on the car unless it was really badly bent. We are talking about tenths of a degree for both toe and camber to go from in spec to out of spec.

    If you are contemplating replacing the axle beam yourself, you should download the axle and suspension sections from TIS (Tech Info Services) https://techinfo.toyota.com/techInfoPortal/appmanager/t3/ti?_nfpb=true&_pageLabel=ti_home_page&SMENC=ISO-8859-1&SMLOCALE=US-EN&SMAUTHREASON=0&SMAGENTNAME=%24SM%24mT%252bGLraBu9CwUVnZg4mEDzB2kysT90hgbwsWgdZzNOc%253d&TARGET=%24SM%24https%3A%2F%2Ftechinfo.toyota.com%2Fpublic%2Fmain%2Fmain.html

    If you have the equipment to raise and support the vehicle, I don't see why you wouldn't be able to swap out the axle beam, but it does look like a significant amount of labor to me.
     
    #7 dogfriend, Nov 24, 2008
  8. butchbs1985

    butchbs1985 Taking things apart is fun!

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    Thanks very much for the response. When the alignment was completed, it was indeed in spec. He just did not sound confident that it would stay that way.

    I had never dealt with this particular dealer before so I think I'll take it to my dealer for an alignment check just to see what they say. Do you happen to have a link to the shim kit? If not, I'm sure I can find it. Thanks again for your fantastic response!
     
    #8 butchbs1985, Nov 25, 2008
  9. dogfriend

    dogfriend Human - Animal Hybrid

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    I used a custom made shim on my car, but there is an aftermarket shim available from this company:

    Specialty Products Corporate Home Page

    I took a couple of screenshots, posted below; click on suspension products, then search for Toyota passenger cars, Prius, 2001 - 2008.
     

    Attached Files:

    #9 dogfriend, Nov 25, 2008
  10. butchbs1985

    butchbs1985 Taking things apart is fun!

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    Thanks! I'll get the alignment checked after the holiday and proceed as needed from there.
     
    #10 butchbs1985, Nov 25, 2008
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