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Sealed Bearings In Transmissions

Discussion in 'Early CJ5 and CJ6 Tech' started by WYOMIKE, Nov 7, 2018.

  1. WYOMIKE

    WYOMIKE Oct 1971 pic

    A post about transmissions brought up something I remembered a long time ago. In our area next to the mountains it is pretty common to have to spend 3-4 hours in low range climbing up the side of some big steep hill. Back in 71 when I bought my jeep the fad was to replace the rear open bearing in the transmission with a sealed one to keep the transmission oil from draining back into the transfer case when going up a long steep hill or the other way around when going down hill a long time. Everybody did it including me (T-14) soon after bought it. Also seems like we had to plug a couple of small holes also. Please keep in mind this was 47 years ago, so my memory it not that great. Heck I have a hard time remembering what I had for breakfast this morning. Anyhow I have never heard anybody talk about doing this on the forum. Never had any transmission problem and that bearing is still there. So don't know if it helped or not.
    Anybody have any thoughts about this? At the time it seemed like a pretty good idea and like I said everybody around here was doing it. :confused:
     
    ITLKSEZ likes this.
  2. Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Sealed front bearings are a popular mod for the T90, not really sure how well it works but I did it anyhow.:shrug:
     
  3. 1957Willys

    1957Willys Member

    You can also remove the inner seal from the bearing so gear oil can lubricate it from the transmission.
     
    Hellion likes this.
  4. TIm E

    TIm E Aggressively average

    Brian talks about this in the following video, starts around the 30 min mark...

     
  5. jpflat2a

    jpflat2a what's that noise?

    Our parts manager lost two T14 front bearings and main drive gear on his 70 due to a long slow hill climb out in our area.
    So he did the same as you described back in the early 70's. No more problem.
     
  6. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    The T-90 has a different issue, in that there's either no seal or a felt seal on the input shaft that can drip. The T-14 has a regular neoprene lip seal in the front bearing cap that stps oil in that direction.

    I'd expect the sealed bearing at the rear to de-couple the transmission and transfer case oil levels. This seems like a good idea, although how beneficial it would actually be I don't know. Oil transfer between the units is normally quite slow. How steep and how long would be required to see a difference?
     
  7. Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Same issue, just a different direction :D
     
  8. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Model T Fords (1908-1927) have a similar issue with the front main bearing. Engines are splash-lubed and the front end starves on hills.

    A popular modification is an oil catcher above the (wet) flywheel, with a gravity drain tube to the front bearing bearing.
     
  9. Norcal69

    Norcal69 Out of the box thinker 2024 Sponsor 2023 Sponsor 2022 Sponsor

    I’m running a sealed bearing in the rear of my t-18 due to oil flowing into the transfer case. I removed the inside seal so that the trans would lubricate it.
     
  10. Rick Whitson

    Rick Whitson Detroit Area 2024 Sponsor 2022 Sponsor

    I wish I had known about that when I rebuilt my T 90. I drove my Jeep 50 miles to Toledo and back this summer and had trans dope leaking out of the bell housing, the felt seal is not working. I will pull it out again and fix the problem at some point.
     
  11. garage gnome

    garage gnome ECJ5 welder

    Hmmm, I might have to do this mod in the future.
     
  12. Tomellen

    Tomellen Member

    Do you have a link for Brian's video, don't thin I have seen this one. thanks
     
  13. 71CJ54WD

    71CJ54WD Sponsor

    I put some one side sealed Koyo's in my T18 and one in my Dana 18 but they are yet to be run.