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1970 Cj5 - T90 Bump Start, Now Won't Crank, Rolls Freely In Gear

Discussion in 'Early CJ5 and CJ6 Tech' started by 1970zeej5, Mar 21, 2022.

  1. 1970zeej5

    1970zeej5 New Member

    I recently rebuilt a 1970 CJ5 with a F134 and a T90. Dropped the transmission and put in a new clutch and shifter top with forks. The transmission was working fine before rebuild and the shifter top was weathered, so decided to replace it.

    Started right up with the clutch pressed in OR when in neutral. When I put it into any gear and would let out the clutch, it would stall and there would seem to be no movement/attempt of movement to the driveshaft to move the back wheels.

    I attempted to bump start in gear (turned on the ignition while in gear without clutch pressed in) to see what would happen and now it seems my starter is stuck...

    Now when I try to crank I get nothing, just a slight click at the battery, and the jeep rolls freely when it's in any gear. I can put in R to 3rd and push the jeep and the fan doesn't spin.

    Looking for any "ah-hah, simple fix" before dropping the trans again and sending to a shop...
     
  2. 1970zeej5

    1970zeej5 New Member

    Update: it does go into gear...transfer case slipped to neutral...

    So it will not crank at all in neutral or with the clutch pressed down. Was starting fine before I tried to bump start.
     
  3. nickmil

    nickmil In mothballs.

    Put a breaker bar or ratchet on the crankshaft bolt with transmission in neutral and see if you can rotate the crankshaft.
     
  4. 1970zeej5

    1970zeej5 New Member

    Yes, it rotates.

    I also noticed the crank rotates while in neutral and I push the jeep.
     
  5. Walt Couch

    Walt Couch sidehill Cordele, Ga. 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Shift tower not properly installed.
     
    Rick Whitson likes this.
  6. Rick Whitson

    Rick Whitson Detroit Area 2024 Sponsor 2022 Sponsor

    Welcome from Michigan. What Walt says. I would pull the top off and look in the trans, make sure the shifting forks are in the gears right. Sounds like one is not moving the sliding gear correctly and locking the trans up.
     
  7. jeepdaddy2000

    jeepdaddy2000 Active Member

    ^3^
    Ill bet a shift collar is misaligned. The fork has missed it and the trans in stuck in gear.
     
  8. PeteL

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

    Try bump starting it?

    (Sorry, couldn't resist. :oops:)
     
    Rick Whitson likes this.
  9. 1970zeej5

    1970zeej5 New Member

    Appreciate the feedback. So I will take off the shift tower and do some research to make sure I am aligned.

    After I take it off, should the jeep then be out of gear and crank when I turn the ignition? Or is it likely a gear or shift collar is misaligned/jammed and I will need to mess with the gears to unlock the trans gear? Any issues with trying to start without the shift tower on?
     
  10. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    No experience with the T-90, but if it's like the other 3-speeds, you can see the forks go into the hubs. Put the transmission in neutral (both hubs in the middle of their travel), hold the shift top in neutral, and the forks should drop in to the hubs.

    Might be messy. Duct tape and a piece of cardboard? I think you can line up the forks and hubs easily if you watch what's happening. An inspection mirror might help.
     
    1970zeej5 likes this.
  11. duffer

    duffer Rodent Power

    Yep

    Sort of like the FC side shift T90's and their sloppy shifers that would leave the last gear engaged when you put it into the next. They don't work well with two gears engaged at the same time.
     
  12. PeteL

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

    I don't understand what the shift tower would have to do with it not cranking with the clutch disengaged?
     
    Rick Whitson, Glenn and Fireball like this.
  13. Glenn

    Glenn Kinda grumpy old man Staff Member

    X 2! Unless the battery is dead.
     
  14. Walt Couch

    Walt Couch sidehill Cordele, Ga. 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Your not reading it all the way through from step to step. He tried to crank it after getting the starter jammed up. See post #2.
     
  15. colojeepguy

    colojeepguy Colorado Springs

    You'll have a fountain of gear oil. BTDT
     
    timgr and Glenn like this.
  16. Glenn

    Glenn Kinda grumpy old man Staff Member

    Yeah, but is it still jammed? Or is the battery low and not turning the starter over?
     
  17. Glenn

    Glenn Kinda grumpy old man Staff Member

    It's weird how gears spinning in oil will sling it.
     
    timgr likes this.
  18. 1970zeej5

    1970zeej5 New Member

    Physics and gravity, things that never quit...

    I realigned the forks and the shift collar per some handy pictures I found online. Transmission issue is fixed and she rolls nicely in neutral and goes into 1-3.

    Took the starter off and tested it and it's now looking like solenoid or starter failure, so taking it to the shop for a rebuild. Funny how the 1 thing I didn't replace in a rebuild fails....

    Shift forks were definitely misaligned and when I tried to start in gear that finished off the starter.
     
  19. Glenn

    Glenn Kinda grumpy old man Staff Member

    I'd consider it a blessing in disguise that the starter failed when it did. :)
     
    Rick Whitson and Bondo like this.