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Trans Jumping out of gear

Discussion in 'Early CJ5 and CJ6 Tech' started by Leathernek, Mar 31, 2012.

  1. Leathernek

    Leathernek Member

    When I got the '63 CJ5 all together this afternoon, I drove it around the block a couple of times, and the transmission kept jumping out of 2nd gear. What would cause this? I know it may need a clutch or it needs adjusting but I just thought it was strange that it was just coming out of gear like that.....:?

    Thanks,

    Josh
     
    Leathernek, Mar 31, 2012
    #1
  2. PeteL

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

    Pretty common in an early CJ5 needing a transmission rebuild, especially if it jumps out when coasting against engine compression downhill, etc.

    Not real complicated or expensive for an F-head.
     
    PeteL, Mar 31, 2012
    #2
  3. Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Generally it's the synchros but has also been blamed on worn bearings (including the pilot bushing) and, at least in my case, a busted poppitball spring in the shift tower.

    Anyway you shake it you're headed for a tranny rebuild.

    H.
     
    Howard Eisenhauer, Mar 31, 2012
    #3
  4. mortten

    mortten I can’t put my finger on it 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Second gear famous for going bad in T-90's
     
    mortten, Mar 31, 2012
    #4
  5. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Supposedly the bronze bushing inside of second gear wears. This allows the gear to skew on the shaft when decellerating, pushing the synchromesh teeth apart and disengaging.

    New second gears are available that will fix this problem.
     
    timgr, Mar 31, 2012
    #5
  6. JeepPower

    JeepPower Hopeless Gearhead

    I had the exact problem.

    For me it turned out to be a spun front thrust washer on the countershaft. The worn bushing allowed the countershaft to move excessively.

    The spun bushing also caused significant wear on the machined surfaces on the case & countershaft. Both the trans case & countershaft had to be replaced.

    Hopefully it is something as simple as a worn syncro assembly, but it wasn't for me. I reused the old syncros & the problem didn't return.

    cell post
     
    JeepPower, Mar 31, 2012
    #6
  7. garage gnome

    garage gnome ECJ5 welder

    Sounds like I have this same problem in my '49 also. I plan on taking the body off this winter to fix some rust issues. Maybe I'll fix it then.
     
    garage gnome, Mar 31, 2012
    #7
  8. nickmil

    nickmil In mothballs.

    First check and make sure the retaining nut is tight holding the transfer case input gear on. If this nut comes loose it will allow the mainshaft to move back and forth causing this problem.


    Sent from my iPhone using Tapatalk
     
    nickmil, Mar 31, 2012
    #8