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

Low-pitch grind in reverse and during regen braking

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by kcj, Aug 30, 2016.

  1. kcj

    kcj Junior Member

    Joined:
    Apr 6, 2016
    22
    5
    0
    Location:
    St Petersburg, FL
    Vehicle:
    2006 Prius
    Hi all!

    I believe [fear] the problem here is the transaxle and it's either got some metal that needs to to be removed, or it's kaput entirely. This would be the second replacement in 6 months, so not thrilled about that.

    Anyway, the symptoms:
    1. During braking, from about 40mpg down to about 15mpg, there is a subtle but noticeable grinding noise coming from the engine compartment, transaxle area
    2. If in Neutral, there is no grinding (MGs are disengaged in Neutral)
    3. When in reverse, any acceleration makes a squeeky/grindy noise
    4. It's not the brake actuator (it was also recently replaced and makes a healthy noise when re-compressing after brake usage)
    5. It's not the brake pads/rotors--they are fairly new, installed myself, and there is never a peep when in neutral and only using the conventional brakes at any degree of pressure
    6. There was a inverter/mg coolant pump failure shortly before this started. It was only driven a few miles after the failure in order to get home. I replaced it with a brand new one at home and it worked like a champ and is still working great.
    7. I've checked the fluids, they're fine
    So, I'm hoping someone will say "oh no it's not the transaxle it's only this small $30 part you can replace in 20 minutes" but I accept any confirmations, albeit begrudgingly, that it is a transaxle issue. What I would like to know is thoughts on whether it is some sort of bearing failure or maybe just some metals cycling around in one of the MGs which could be removed with a few flushes.

    Your thoughts are appreciated!

    (2006 2nd Gen Prius with 164k miles. Had the transaxle replaced about five months ago at GreenTec Auto)
     
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    108,810
    49,429
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    how many miles on the replacement tranny? no warranty?
     
  3. kcj

    kcj Junior Member

    Joined:
    Apr 6, 2016
    22
    5
    0
    Location:
    St Petersburg, FL
    Vehicle:
    2006 Prius
    Hi Bisco,

    I was never told how many miles were on the replacement they put in. We agreed to a warranty of 18months for labor only as they could not warranty a salvage yard part. Unfortunately, the part is quoted as $1200 and the labor is $800, so the crux of the job was in parts which I would have to pay for again. A used transaxle doesn't cost $1200 at the yard, but I suppose that cost includes removal and transport fees as well. In any case, I now know a Prius mechanic who says he replaces the entire engine and transaxle at once for no more than $1500, so it would almost be a better value to do that.

    I simply don't want the transaxle to be a problem again, it's a little disheartening to have repeated repair needs back to back. Transaxle, then brake actuator, then coolant pump. I got a good deal buying the car, so I figure I'm at the break even point now, so spending a bit more isn't the end of the world. However, it is starting to feel like a money pit and I don't want that to be the case. It's supposed to save money, but currently we're in the negative.
     
    bisco likes this.
  4. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    108,810
    49,429
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    weren't the actuator and coolant pump covered under extended warranty? was it the inverter pump?

    i would definitely check with greentec, a low mile tranny price should cover everything but transportation, which isn't much. seems there $1,200. is inflated.

    anyway, i hope it isn't the tranny either. all the best!(y)
     
    kcj likes this.
  5. JC91006

    JC91006 Senior Member

    Joined:
    Nov 10, 2013
    16,479
    8,397
    0
    Location:
    Los Angeles, CA
    Vehicle:
    2008 Prius
    Model:
    II
    You can find a used transaxle on ebay for about $300-$500 delivered. You can get one of those if Greentec says the transaxle is bad.....which they really should warranty.
     
  6. kcj

    kcj Junior Member

    Joined:
    Apr 6, 2016
    22
    5
    0
    Location:
    St Petersburg, FL
    Vehicle:
    2006 Prius
    Thanks JC. Now that I think of it, I believe they did warranty the part. In any case, I'm hoping to not even need to go down that road. I will do a trans fluid change and see if I can get anything out of there.
     
  7. JamesG123

    JamesG123 Junior Member

    Joined:
    Dec 30, 2016
    72
    18
    3
    Location:
    Venice Beach, CA
    Vehicle:
    2004 Prius
    Model:
    Two
    Kcj, did you fix it? What was the problem?
     
  8. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    10,096
    4,805
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    Any suspected grinding can be confirmed by dumping trans fluid and inspect fluid. Check dump bolt magnet for metal debris. Should only be metal paste on that magnet. Any particles and trans is toast.If non ferrous metal loss put old fluid in wide container and out in sun and you will see a lot of bright metal floating around in it,
    Been a few posts about diff section gear failure and luscious garage talks about bearing failures in Prius taxis.
    All caused by poor maintence coupled with super duty use I imagine.