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T90 Countershaft Leak

Discussion in 'Flat Fender Tech' started by CJMark, Mar 5, 2018.

  1. Mar 5, 2018
    CJMark

    CJMark Jeeper

    Spearfish, SD
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    Mar 7, 2014
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    102
    Does it look like a new countershaft is in my future? I don’t remember them recessed that far. I’ll take transfer case off tomorrow and see if keeper in place. I’ll probably end up replacing it, any tricks to sealing these? I thought these are tapered and press fit to keep from leaking.
    Thanks


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  2. Mar 5, 2018
    TIm E

    TIm E Aggressively average

    NW Arkansas
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    Pretty incriminating picture there as to the source of the leak. I am not familiar with the T90, but when fully installed with the keeper snug on my T14, the front side of the shaft is flush with the case.

    I also put a thin layer of Permatex anerobic gasket sealant in that bore. The shaft pushes most of it out, but cheap insurance. I did the same on my D18 intermediate shaft bore.
     
  3. Mar 5, 2018
    mike starck

    mike starck Member

    salem,oregon
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    Jun 22, 2006
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    Just finished a repair on a T-14a with the same problem. It seems that with the synthetic oil leaks happen where they didn't in the past. Or the parts are really old.
    I did a fix on it .Will wait to see what the T-90 guys have done. mike
     
  4. Mar 6, 2018
    CJMark

    CJMark Jeeper

    Spearfish, SD
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    I’ve thought about knocking shaft back just a bit where thrush washer still on, cleaning bore, Permatex, push shaft back, cut circular rubber/cork gasket washer for bore hole, more Permatex, cut gasket for face of T90, more Permatex and slap back together.

    But I’m going to dissemble and measure play in bore/shaft and see how much wear and go from there. More fun with beloved Willys
     
  5. Mar 6, 2018
    Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Tantallon, Nova...
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    If you have any at all there's something seriously wrong- that's not a wear point unless the shaft itself has been turning. :shock:

    I put RTV in there when I rebuilt mine, I suppose you could grove the end & install an o-ring if the case bore has somehow wallowed out.
     
  6. Mar 6, 2018
    TIm E

    TIm E Aggressively average

    NW Arkansas
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    Interestingly, the Novak D18 intermediate shaft is grooved for o-rings at both ends. What had me stymied is how to get the leading (front) o-ring through all of the needle bearings and spacers without it getting all wadded up in there...and how would I know it made it through safely?? I ended up leaving it off and going with the sealant in the front bore. I did use the o-ring on the rear/keeper side since it does not have to travel through the bearings and spacers. I'd be interested to hear other's thoughts on this...I was not brave enough to try it.

    Be careful with synthetics and modern oils with higher GL ratings in these applications. The extreme pressure additives have been shown to eat bronze (bushings, thrust washers and blocking rings).
     
  7. Mar 6, 2018
    Alan28

    Alan28 Well-Known Member 2022 Sponsor

    Châtillon en...
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    about oils I asked long ago to a guy working for a oil factory mainly for aviation. He told me not to use modern oils.
    about leaks last year I paid a pro shop to stop oil leak at transfer case, he changed the o ring and now the cj5 is perfect.
     
  8. Mar 6, 2018
    CJMark

    CJMark Jeeper

    Spearfish, SD
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    Good call, there was something serious wrong, shaft was spinning due to no lock plate. End of both counter and reverse shafts had small spot weld, which did nothing, not sure why, maybe too lazy to line up shafts for lock plate. I have some good thrush washers and old lock plate from previous rebuild so hopefully running again end of week. Glad I dissembled instead of Permatex patched to find cause of leak.


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    Dang it Focker, you’re beam it cloud icon is slick.
     
    Danefraz likes this.
  9. Mar 6, 2018
    Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Tantallon, Nova...
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    I figured the was no lock plate 'cause the shaft moved back, I am surprised it was actually turning though. o_O
     
  10. Mar 8, 2018
    Keys5a

    Keys5a Sponsor

    Florida Keys
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    Before you re-assemble the trans, check the fit of the countershaft in the case to make sure it is a snug to tight fit. With it previously rotating in the case, either the shaft or the case could have worn, more than likely the case side since the shaft is hardened. If there is any play in the fit, it will leak again.
    -Donny
     
  11. Mar 9, 2018
    CJMark

    CJMark Jeeper

    Spearfish, SD
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    Another good call from experienced mechanic, case slightly worn from rotating shaft but last part of install tight. All buttoned up and installed, fluid tomorrow (GL-1 mineral oil, Ford tractor transmission fluid) and road test next couple days. I’m optimistic leak free and less drivetrain noise in cab.

    Cut full gasket to match bell housing backed with Gear Oil RTV Gasket Maker as a little insurance. Another good day wrenching on the old Willys.


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    tripilio likes this.
  12. Mar 9, 2018
    mike starck

    mike starck Member

    salem,oregon
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    That looks good.On my T14 the shaft leaked because I didn't get the RTV around the shaft and case good enough.Second try was RTV around shaft,wait to cure,cut off excess with razor and make gasket to cover face of trans (as you did) with Felpro 1/32" grey gasket material.Bond to trans with 3M weatherstrip cement.All back together and road tested with no leaks anywhere. mike
     
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  13. Mar 25, 2018
    CJMark

    CJMark Jeeper

    Spearfish, SD
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    All buttoned up and about 50+ miles on so far and no leaks. Hopefully drip free will last.

    In addition to above trany to bell housing gasket, I have gear oil gasket maker between trany and TC, especially on lower bolts, “right stuff” gasket maker on TC pan, double National 473229 seals on rear TC yoke.

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  14. Mar 26, 2018
    Keys5a

    Keys5a Sponsor

    Florida Keys
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    Imagine that. A transmission and t-Case that doesn't leak!
    Good work -Donny
     
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  15. Mar 26, 2018
    GeorgiaFlattie

    GeorgiaFlattie Member

    Canton, GA
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    I'm curious to see if the additional full face gasket causes any sort of unintended issues down the road. Looks like a good solution to the problem though.
     
  16. Mar 26, 2018
    CJMark

    CJMark Jeeper

    Spearfish, SD
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    Thanks Donny.
    Takes perseverance, common sense, attention to detail, experience and Jeep forums, can be done, my ‘71 with Dana 18 leak free over a year and many miles.

    I wonder how many T90 owners don’t know that a T90, both column and cane shift, came with front gasket? Makes sense, several leak points on front. And there’s 3 different National seals for the yokes, one is better than other 2 based on my experience.
    Mark
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  17. Mar 27, 2018
    GeorgiaFlattie

    GeorgiaFlattie Member

    Canton, GA
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    Learn something new every day. Thanks.
     
  18. May 12, 2020
    Keys5a

    Keys5a Sponsor

    Florida Keys
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    I know this is an old post, but never followed this thread to the end.
    My comment is, yes, there is supposed to be a gasket between the trans front face and bellhousing, but this gasket is very thin paper. I'm afraid that even a fairly thin gasket out of anything thicker than paper will allow for potential movement between these surfaces that should be tight. I would also be afraid of breaking the transmission case "ears" when torquing the bolts when using a thick/soft gasket.
    If I don't have a paper gasket handy, I usually spray both surfaces with Permatex copper spray when I assemble them.
    -Donny
     
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