Oil leak between engine and gearbox

Discussion in 'GS Boxers' started by Djensen, Oct 18, 2016.

  1. Djensen

    Djensen n00b

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    Dear inmates, while cleaning my 2012 1200 GS twin cam this weekend, I noticed oil on the bash plate. I removed the bash plate and could see oil apparently coming from the flange between the engine and the gearbox, mostly on the left side in the area of the starter motor. Could this be a leaking main bearing oil seal or gearbox input shaft sealing meaning that the bike will have to be split in 2 to get it fixed ? Have any of you experienced this on a 2012 twin cam? Mileage is 33400 km.

    Attached Files:

    #1
  2. Lounge

    Lounge Been here awhile

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    Not sure where the leak is coming from but if it is the main seal or input shaft you will need to separate the engine from the trans. And if you're going to separate the two, you may want to replace both seals for peace of mind. Also, plan for replacing the clutch friction plate if you find it's saturated with oil.

    Sounds like you found a winter project.
    #2
  3. Steptoe

    Steptoe steptoe

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    Most of the oil leaks i've worked on from that area have been the counter balance shaft seal.
    #3
  4. Britome

    Britome Get Free

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    +1


    Sent from my iPhone using Tapatalk
    #4
  5. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

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    Same here. The bike needs to be split to fix it, possibly also need to replace the clutch.

    [​IMG]
    [​IMG]
    [​IMG]
    #5
  6. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

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    No, it is inside the clutch housing, not directly exposed to the elements.

    In this photo you can see the lower part of the flywheel.

    [​IMG]

    The balancer is exposed to clutch dust, but that is not an issue.
    #6
  7. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

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    They failed a fair bit back in 2005 and 2006. Pretty rare for a Camhead. Also, once the seal is replaced, it usually stays fixed.
    #7
  8. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

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    Though the Hexhead and the Camhead motors look a lot alike, they are completely different. The seals are the same though.

    Hexhead:
    10 11 11 7 721 848 SHAFT SEAL - 25X37X6,5 0.02 1 $26.98[​IMG]
    [​IMG] [​IMG]
    [​IMG] [​IMG]

    01 11 11 7 701 989 ENGINE HOUSING, SILVER 26.29 1 $1642.48

    Camhead:
    09 11 11 7 721 848 SHAFT SEAL - 25X37X6,5 0.02 1 $26.98[​IMG]
    [​IMG] [​IMG]
    [​IMG] [​IMG]

    01 11 11 7 713 663 ENGINE HOUSING, SILVER 29.76 1 $1675.30[​IMG]
    #8
  9. Djensen

    Djensen n00b

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    Thanks for your replies. I am considering to do the job myself during the winter months where it is not possible to ride anyway.

    @jim: is it necessary with special tools to remove the old seal - a puller or? Or can I just carefully drill a small hole in the seal outer ring and insert a screw or threading tool and pull the seal out that way? I guess it will be necessary with a clutch alignment tool also ( cheap on EBay)?
    #9
  10. Steptoe

    Steptoe steptoe

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    Drill a hole and insert a screw, jesus christ..
    Just unscrew the end of the balance shaft and pull it out then you can use a finger to pull the seal out :D
    #10
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  11. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

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    :nod Or a simple screwdriver if it is stuck.
    #11
  12. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

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    No need for a clutch alignment tool. I have always had good luck with just a 3/8" 6" extension and eyeballing it. The end of the trans input shaft doesn't meet the engine, it just floats, so close is close enough.
    #12
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  13. lkchris

    lkchris Albuquerque

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    Had rear main and balancer shaft seals replace on my 2012 R1200RT while still under warranty.
    #13
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  14. 06motorradman

    06motorradman Been here awhile

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    I am in the process of replacing my counterbalance shaft seal. My RepRom says to discard the old bolt that holds the weight to the shaft, then install a new bolt (10 Nm + 90 degrees). Is this a stretch bolt? Must it be replaced?
    #14
  15. ErikMotoMan

    ErikMotoMan Airbag crash survivor!

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    Yes, there's a reason replacement is specified. 10 NM isn't a lot of torque, so I'm guessing it is a stretch bolt.
    #15
  16. Steptoe

    Steptoe steptoe

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    I've never ever replaced that bolt, always used the old one without any problems, and i've done a fair few over the years :D
    #16
  17. Plymouth GTX

    Plymouth GTX Adventurer

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    Hi all I was reading the above post on the oil leak and I checked my 2012 gsa and it is also leaking must have just started in the last month was just wondering if the extended warranty would cover this I have (Pinnacle) extended till 2018. Thanks for any replys KB9GIB
    #17
  18. JimVonBaden

    JimVonBaden "Cool" Aid! Supporter

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    It should.
    #18
  19. Plymouth GTX

    Plymouth GTX Adventurer

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    Thanks Jim I will call tomorrow and ask maybe I will not have to do it. i do thank you for your reply.
    #19
  20. kevin g

    kevin g Been here awhile

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    I have an oil leak here on my 2011 GSA that developed on my return from Alaska so I will be splitting my bike as well. I have some questions:

    1) If it is only the counter-balance shaft seal should I leave the rear main alone? I am inclined to do both of them while in there and all of the trans seals.
    2) I have seen on other threads that there is a special tool for the rear main seal. Has anyone done the rear main without using the special tool? I have a lathe so could make something if needed.
    3) Should I buy the RepRom CD? I have seen great posts on splitting the bike but have not found one in the search so far.
    #20