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D18 Leaking - Advice Please

Discussion in 'Early CJ5 and CJ6 Tech' started by Jeepman31, Jun 11, 2017.

  1. Jun 11, 2017
    Jeepman31

    Jeepman31 New Member

    Colorado, USA
    Joined:
    Jan 19, 2017
    Messages:
    47
    Timgr suggested I start a new thread with this, so here goes:

    My transfer case output shaft seal is leaking, as are the shims between the speedo gear housing (transfer case bearing cap) and t-case.

    I've read most of the old threads about leaking d-18's, so here is my plan. Let me know what you guys think.

    1. Replace the output shaft seal - National 472635 or 473229. The yoke/companion flange seal surface doesn't have any grooves, so I am reusing it.

    2. Coat both sides of each of the shims with Permatex No. 3. The shims are a little pitted so I am hoping the Permatex will fill in the gaps and create a seal.

    3. Put ultra-black RTV on the splines inside the Companion Flange.

    4. And, while I am at it, reseal the t-case pan with Permatex Right Stuff, with a dab of the sealer on each of the bolt threads.

    5. Install a brake backing plate to transfer case bearing cap gasket. There wasn't one there when I disassembled.

    Is there anything I missed in my attempt for a leak-free D18?

    I already re-sealed my Warn overdrive with decent results. So I have high hopes for stopping the leaks!

    One other thing,

    I pulled the speedo driving gear off before noting its orientation. Duh! Does it matter which way this goes back on?

    IMG_0109.jpg

    Thanks, I appreciate the help. This forum is the best!!!
     
  2. Jun 11, 2017
    Twin2

    Twin2 not him 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Virginia Beach, VA
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    Last edited: Jun 12, 2017
  3. Jun 11, 2017
    wheelie

    wheelie beeg dummy 2024 Sponsor 2023 Sponsor

    York, PA
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    Mar 6, 2004
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    I used the Permatex in the green tube when I rebuilt mine but, it's still sitting on the bench so, I cannot comment on it's performance. I used it because it says on the package that it is specifically for gear lube. Just a thought.
     
  4. Jun 12, 2017
    Jeepman31

    Jeepman31 New Member

    Colorado, USA
    Joined:
    Jan 19, 2017
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    47
    Thanks for the tip on the gear oil Permatex wheelie.

    I think I'm going to try doubling up on 473229 - two of those stacked on top of each other should stop the leak permanently. (I hope)
     
    Bill Cosler likes this.
  5. Jun 12, 2017
    wheelie

    wheelie beeg dummy 2024 Sponsor 2023 Sponsor

    York, PA
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    I used the spray on copper sealant on the shims under the advice of a member here. I was told that it is less likely to throw off, or affect, the thickness of the shim pack.
     
    Posimoto likes this.
  6. Jun 15, 2017
    CJMark

    CJMark Jeeper

    Spearfish, SD
    Joined:
    Mar 7, 2014
    Messages:
    102
    Jeepman, looks like you have good plan to stop leak. Please report back on results when back together with a few miles on Jeep. I'm about ready to tackle my annoying leak. Thanks
    Mark

     
  7. Jun 15, 2017
    AKCJ

    AKCJ Active Member

    Fairbanks, Alaska
    Joined:
    Aug 12, 2003
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    1,035
    I built a small sheetmetal drip pan that sits below the t-case and above the skid plate. The t-case still leaks a bit but not on the floor.
     
  8. Jun 15, 2017
    wheelie

    wheelie beeg dummy 2024 Sponsor 2023 Sponsor

    York, PA
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  9. Jun 15, 2017
    Jeepman31

    Jeepman31 New Member

    Colorado, USA
    Joined:
    Jan 19, 2017
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    47
    Thanks for all of the input guys. I just re-sealed the transfer case oil pan with Permatex "The Right Stuff". I was very happy with how the sealant applied to the pan, it seemed very tacky and I believe it will make a good seal. I also put a dab of the sealant on each pan bolt. I'm still gathering parts together, and will keep chipping away at the project as I have time. I'll definitely post an update once I get it all together again. Hopefully everything will be leak free.

    I bought some Permatex copper spray for the shims. I am going to assemble dry first and check the endplay on the output shaft, just for peace of mind. The shims are the part I'm a bit worried about as far as leaks go. I hope the copper spray does the trick.

    I like the idea of the drip pan AKCJ. I could almost collect all the drips and pour them back in every week, LOL.

    Wheelie, I also picked up some of that Permatex Gear Oil gasket maker. I plan on using it on the yoke splines.

    This Jeep has definitely been a challenge, but I'm sure the end result will be worth the work. I do love these old Jeeps!
     
  10. Jun 21, 2017
    CJMark

    CJMark Jeeper

    Spearfish, SD
    Joined:
    Mar 7, 2014
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    102
    I'm leak free for now. Put in two seals (473229) on T18 output and used the Permatex Gear Oil RTV to seal everything up. Thought about using the wider National 450185, but since there's room put in the double seal. Cheap fix, just two and half days of labor. Hopefully it last.
    Thanks contributors for pointers.
    Mark
    [​IMG]
     
    Last edited: Aug 1, 2017
    75 DJ likes this.
  11. Jul 1, 2017
    71CJ5Renegade

    71CJ5Renegade 71cj5RenegadeII

    Bulverde, TX
    Joined:
    Dec 27, 2007
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    I could never get my Dana 18 pan to stop leaking, installed the Novak adapters billet pan cover and haven't had any issues since.
     
    OrangeCJ5 likes this.
  12. Jul 10, 2017
    Jeepman31

    Jeepman31 New Member

    Colorado, USA
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    Jan 19, 2017
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    Update: The yoke is leak free. Yeah! Stacking two 473229's on top of each other did the trick.

    The pan still does have the tiniest seep at the lowest corner, even with Permatex Right Stuff gooped all over it. I concur with 71CJ5Renegade - the Novak pan is probably the only way to stop the Dana 18 pan from leaking permanently.
     
    CJMark likes this.
  13. Jul 29, 2017
    Burndoubt

    Burndoubt Member

    Vermont
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    Apr 12, 2017
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    51
    Can anyone tell me if the Novak pan will fit with the drive shaft parking brake? The arm is pretty close to the bottom of the stock pan.
     
  14. Aug 15, 2017
    Jeepman31

    Jeepman31 New Member

    Colorado, USA
    Joined:
    Jan 19, 2017
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    Update - the t-case is slowly leaking through the shims again, which I thoroughly coated in Permatex copper spray before re-assembling. I can actually see particles of the copper mixed in with the gear oil that is dripping. I'm really at a loss here... The shims were flat and not corroded, and all of the bolts where properly torqued down.

    Should I just give it up and move on with life? :n:
     
  15. Aug 15, 2017
    CJMark

    CJMark Jeeper

    Spearfish, SD
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    I'd give it another shot since it's an easy area to access. Mine is still leak free, but I had used the black liquid aviation sealant on the shims, the "black smack" has always been my go-to sealant for gaskets. The gray gear oil RTV works great in other areas including splines/bolts.
    Mark

    [​IMG]
     
  16. Aug 15, 2017
    Jeepman31

    Jeepman31 New Member

    Colorado, USA
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  17. Aug 15, 2017
    Broylz

    Broylz Member

    Gallatin, TN
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    Oct 9, 2012
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    Have to follow this. Will be rebuilding my d18 soon.
     
  18. Aug 15, 2017
    Rozcoking23

    Rozcoking23 RUN & GET BIT! 2024 Sponsor

    Stockton, CA
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    Just finished putting in the double seal (473229), and replaced the shims and used the Permatex copper spray, then replaced the pan gasket and oil bearing cap to brake backing plate gasket. I used Permatex RTV gear oil gasket maker on the pan gasket and pan bolts. Also used a little of this on the splines of the yoke. I also replaced the brake pads (oil soaked). Been a week and no leaks so far. (y)
     
    CJMark likes this.
  19. Aug 15, 2017
    Jeepman31

    Jeepman31 New Member

    Colorado, USA
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    Jan 19, 2017
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    My leak came back slowly after driving the Heep a few times. I don't think the copper spray holds up well against gear oil. I called Permatex and they recommended I try their anerobic gasket maker -

    https://www.amazon.com/gp/aw/d/B000...8df-4dd0-be50-91c6a4b9661a&pd_rd_i=B0002UEONM

    This gasket maker is thin enough that it will not mess with the clearance set by the shims.

    It's a pain, but I'm going to pull it apart and try again.
     
  20. Aug 15, 2017
    Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Tantallon, Nova...
    Joined:
    Nov 22, 2003
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    8,102
    I used the red spray on gasket sticky stuff, no leaks so far after a couple of years.

    [​IMG]

    H.
     
    Broylz likes this.
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