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

Leaking transaxle oil from both sides of case. Seal issue?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by LeakyPrius, Mar 5, 2015.

  1. LeakyPrius

    LeakyPrius Junior Member

    Joined:
    Mar 5, 2015
    18
    1
    0
    Location:
    LA
    Vehicle:
    2006 Prius
    Model:
    N/A
    Hi guys, I bought a used salvage 2006 Prius with ~80k miles on it about a year and a half ago and have only changed the transaxle fluid when I got it, the HID bulbs ~90k miles, and engine oil of course.

    While I was changing the oil today I noticed dust buildup and pink oil on the transaxle case (?) both on the left and right side of it. It wasn't dripping, just built up on the case so there's definitely a leak somewhere, just small enough not to be too big of a worry for now, at least I hope.

    I've included pictures of where the oil is building up but can't seem to find the source or a reason. Note that I wiped the left side with my finger to confirm it's oil and not coolant. Is the transaxle case itself leaking or is it a seal somewhere?

    [​IMG]

    [​IMG]

    Thanks!
     
  2. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,910
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    The fluid appears to be leaking out of the casing joints. I could be wrong but it looks like the casing has been dismantled and re sealed "possibly due to the rebuild." It does not look like a major issue so I would leave well a loan.

    John (Britprius)
     
    #2 Britprius, Mar 5, 2015
    Last edited: Mar 5, 2015
    LeakyPrius likes this.
  3. LeakyPrius

    LeakyPrius Junior Member

    Joined:
    Mar 5, 2015
    18
    1
    0
    Location:
    LA
    Vehicle:
    2006 Prius
    Model:
    N/A
    Could it be that I didn't tighten the transaxle drain/fill nuts tight enough for it to seep out from the case like that or would it only leak from the drain/fill hole areas if that was the case?

    I remember taking off the drain/fill nuts was extremely difficult and even stripped the nuts a little bit. I doubt I torqued the two bolts as hard as they originally were.
     
    #3 LeakyPrius, Mar 5, 2015
    Last edited: Mar 5, 2015
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,198
    6,461
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    The leaks have nothing to do with the drain/fill plugs.

    Look at the axle shafts which come out of both ends of the transaxle, to see whether oil is leaking at those points. If so, then the seals need to be replaced. Otherwise it would appear that the case is leaking at a seam.
     
  5. LeakyPrius

    LeakyPrius Junior Member

    Joined:
    Mar 5, 2015
    18
    1
    0
    Location:
    LA
    Vehicle:
    2006 Prius
    Model:
    N/A
    Would I have to remove the casing or should I be able to spot these shafts just by getting under the transaxle?

    I tried looking around the front but couldn't spot any shafts originally, I'll jack it up and try again if I'm just looking in the wrong spot.
     
  6. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,910
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    The shafts are to the rear of the transmission, and go out to the wheels. However from your pictures the oil does not appear to be coming from that area.
    In your first picture you can see the wheel end of one of the shafts going into the large rubber boot to the right of the picture. Following that shaft inwards you will come to another rubber boot that covers the inner CV joint this in turn is fitted into the transmission. Where it enters the transmission there is a seal "one each side of the transmission for each shaft". These seal are often the cause of leaks.

    John (Britprius)
     
  7. LeakyPrius

    LeakyPrius Junior Member

    Joined:
    Mar 5, 2015
    18
    1
    0
    Location:
    LA
    Vehicle:
    2006 Prius
    Model:
    N/A
    I tried looking around the sides of the transaxle but couldn't see any sign of oil dripping, at this point I think oil is just somehow leaking out of the case. Is there any way I can seal it back up, maybe apply some kind of adhesive/epoxy around the case joints or should I just leave it be and just top off the transaxle fluid every now and again?
     
  8. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,910
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    The leak looks very minor. You will get an idea how much it is leaking from how much staining there is on the floor where it is parked. If little or no staining is found check the level say twice a year maybe after 3 months the first time.
    I do not think you will be able to seal it externally, but you could just make sure the bolts are tight in that area.
    The transmission works with a slight internal vacuum. This is created by the air in the transmission expanding when the transmission gets hot pushing out through a one way valve on the top of the transmission. When it cools the vacuum is created.

    John (Britprius)
     
    LeakyPrius likes this.
  9. LeakyPrius

    LeakyPrius Junior Member

    Joined:
    Mar 5, 2015
    18
    1
    0
    Location:
    LA
    Vehicle:
    2006 Prius
    Model:
    N/A
    Is there any chance I could overtighten the transaxle bolts by hand and strip them?

    Given my trouble with the fill/drain bolts I'm guessing not but is there a recommended torque value for it?
     
  10. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,910
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    Yes there is a recommended torque value. I will see if I can find it and come back to you.

    John (Britprius)
     
  11. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,910
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    Cover bolts are tightened to 25N-m

    John (Britprius)
     
    LeakyPrius likes this.
  12. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,473
    38,103
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    We've got a Civic in the family with a continuously variable transmission, it's underside's looking oily. The leak seems very light, not dripping. I figure to just keep an eye on it.
     
  13. Yakoma

    Yakoma Active Member

    Joined:
    Oct 17, 2014
    470
    121
    0
    Location:
    ATL-ish
    Vehicle:
    2008 Prius
    Model:
    N/A
    Any chance you can locate the service history for this vehicle and learn if there was a rebuild done on it? The Owners site at New Cars, Trucks, SUVs & Hybrids | Toyota Official Site contains dealer service history if you enter the VIN.

    Having had a bad experience with another car where the tech overtorqued and stripped out the oil pan cover bolts (required a trip to the dealership to remedy the situation), I wonder if something similar could have happened here to cause the issue.

    Doesn't solve the problem, but could lend some insight.
     
    LeakyPrius likes this.
  14. valde3

    valde3 Senior Member

    Joined:
    Jun 28, 2014
    2,002
    745
    0
    Location:
    Finland
    Vehicle:
    2004 Prius
    It looks from the picture that the seam is clean at the top of the picture 1. If it’s then problem is around that bolt. If you can’t tell just clean the oil off and then look at it again after some driving.
     
  15. Britprius

    Britprius Senior Member

    Joined:
    Jun 14, 2010
    5,194
    1,910
    0
    Location:
    Herefordshire England
    Vehicle:
    2008 Prius
    It was a salvage vehicle so it's possible the housing has taken a knock.

    John (Britprius)
     
  16. Yakoma

    Yakoma Active Member

    Joined:
    Oct 17, 2014
    470
    121
    0
    Location:
    ATL-ish
    Vehicle:
    2008 Prius
    Model:
    N/A
    good point
     
  17. LeakyPrius

    LeakyPrius Junior Member

    Joined:
    Mar 5, 2015
    18
    1
    0
    Location:
    LA
    Vehicle:
    2006 Prius
    Model:
    N/A
    Toyota's site doesn't mention anything about rebuilding/servicing the transmission. The salvage title was due to a major crash in the back of the vehicle. At this point I'm just going to wipe it down, tighten the bolts and hope for the best.

    Thanks everyone for all your help!
     
  18. 69shovlhed

    69shovlhed Surly tree hugger

    Joined:
    May 13, 2012
    2,170
    744
    0
    Location:
    Delaware
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Premium
    get a torque wrench and do it correctly. don't guess and make it worse.
     
  19. LeakyPrius

    LeakyPrius Junior Member

    Joined:
    Mar 5, 2015
    18
    1
    0
    Location:
    LA
    Vehicle:
    2006 Prius
    Model:
    N/A
    Yep, already have one and will go by Britprius's 25 N-m spec.
     
  20. maximusdec

    maximusdec Member

    Joined:
    Jul 9, 2014
    107
    52
    0
    Vehicle:
    2007 Prius
    Model:
    II
    Mine has similar leak only on one side, on driver side. Transmission has never been opened. And the drive shaft connection to the transaxle is dry. Am guessing it's sipping through the casing connection there. Do these have gaskets that can be replaced?