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t90 stuck in neutral

Discussion in 'Early CJ5 and CJ6 Tech' started by jossar, Jul 20, 2015.

  1. jossar

    jossar Member

    My significant other's car broke down so she asked if she could use the Jeep to run some errands today. She call around noon to say it was stuck in neutral in the parking ramp down town. I went over to check it out thinking she must have bumped the transfer case to neutral and sure enough the tranny was locked solid in neutral. After about 5 minutes of jiggling and banging on the shifter with the palm of my hand I was able to get it to go into second gear. I tried to drive it (mostly to move it from the handicapped parking space she was in) and I was able to get Reverse, 1st and second but if I tried to go to third it would try to lock up in neutral. I could probably get it home in second (10 or so miles) but I 'm afraid I might do further damage. Any ideas what the problem might be? Should I drive it home in second or try and rent a trailer? The tranny was new in 2012 (probably Omix) and I bet doesn't have 1000 miles on it. 2 down in 2 days - she's not driving my daily driver!
     
    Last edited: Jul 20, 2015
  2. PeteL

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

    Is there (was there) oil in the transmision?
     
  3. jossar

    jossar Member

    There was but honestly I haven't checked it since last fall - don't drive it much. I plan to check that before I move it any further.
     
  4. 68BuickV6

    68BuickV6 Well-Known Member

    I check mine before I drive every time. Curious to see what the issue is.
     
    Last edited: Jul 21, 2015
  5. uncamonkey

    uncamonkey Member

    My neighbor has an old ford tractor that does something like that. The end of the shifter cane is worn out and it will leave one shifter rail in place as you hunt for the next gear. That and make sure all of the shiftter parts inside are good and all of the roll pins and such are good. As you can get into 2nd and reverse, I suspect your shift tower is messed up. I almost messed up, I left the f out of shift at first...
     
  6. wheelie

    wheelie beeg dummy 2024 Sponsor 2023 Sponsor

    I wouldn't be concerned with driving it home, 10 miles, in 2nd. Along as you're not trying to do 50 mph. Take the back roads, drive the shoulder with 4 ways on or whatever. This, of course, after checking the fluid level. Once I got it home, I'd get it in neutral (not where it is locked in neutral but where it feels right, as N should feel when all is right), and remove the top cover and inspect the shifter parts.
     
  7. jossar

    jossar Member

    Well, I pulled the top cover in the parking lot and it was full of oil (almost anyway - less than 1/4" down from the fill plug). I replaced the top cover with the new one that came with the tranny (I had put the original one on when I replaced the tranny because the cane on the new one hit the dash in reverse). As before it shifted fine into reverse, 1st and second but when I tried for third it locked up tight in neutral. This time no amount of jiggling or banging with the palm of my hand will free it up. should of drove it home while I had the chance. Time to regroup and figure out how to get it home I guess.
     
  8. Focker

    Focker That's a terrible idea...What time? Staff Member

    Every time? How long in between drives does it sit?
     
  9. Unkel Dale

    Unkel Dale delivery on my Jeep from Ft. Campbell, Ky.

    The shifter cane that hits the dash board should be heated while being held in a vise and the bent with a hammer so it no longer hits the dash.
    That type of steel in the cane is softer compared to the shafts inside the case.
    Heat it. Beat it. Cool it. Test the arc of the bends against the one you have in the Jeep now that does not work for the pattern.
    Wire brash and repaint.
     
  10. jossar

    jossar Member

    I'll probably just put the old one back on since it's obviously not the problem. The cane is thinner than the new one - the fat cane doesn't look right. I don't know much about the innards of these transmissions but guessing I have an issue maybe with the syncro for 3rd? Maybe dropped a needle bearing? When I had the cover off everything still looked new including the oil.
     
  11. PeteL

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

    With the top off you may be able to manipulate (slide) the gears to get it unstuck. Enough to drive home in second, say.
     
  12. Glenn

    Glenn Kinda grumpy old man Staff Member

    It doing the same thing with both shifters does kinda rule that out. I think next step would be to drain the oil into a clean pan and start looking for any kind of brass, bronze, steel shavings or pieces. If you can't physically see any obvious problem I think I would be looking real hard at the synchro assembly being the problem.
     
  13. jossar

    jossar Member

    I borrowed a trailer and got it home last night. I pulled the shifter back off and the problem was staring me in the face. One of the dogs in the syncro clutch had popped off the spring and jammed forward. After about 2 hours of messing around (including 45 min fishing a small screwdriver out of the bottom of the case that slipped out of my hand) I was able to work it back in place over the spring. All is good - for now. A little concerned that it might happen again - not sure why it happened in the first place. Thanks for all your help.

    [​IMG]
     
  14. 1960willyscj5

    1960willyscj5 Well-Known Member

    If you look at that goldie colored ring in the area where that lug or whatever is sitting, the teeth are all ground off. Probably ought to consider a rebuild on that tranny.
     
  15. Glenn

    Glenn Kinda grumpy old man Staff Member

    Good catch on the wear on the blocking ring. The synchronizing ability is about shot on it. The construction of the synchro assembly is a relatively cheap (as in not strong) design. I would plan on a repair or replacement of it very soon. I believe all of the parts are readily available.
     
  16. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Those are the teeth on the brass blocking rings. The blocking ring fits over a cone surface on the gear, and the synchro collar pushes the blocking ring into the spinning gear and friction on the gear makes the collar and gear match speed. Synchromesh.

    Wear on the teeth isn't a big problem. When the blocking rings wear out, they are loose on the cone and fail to match speeds when shifting - then you get gear clash.

    Me looking at this, I'd say your synchro hub is worn out and allowing the plate to escape its spot. Not really familiar with the T-90, but B-W 3-speeds have a couple of springs that hold those plates in the hub and tight against the collar. One of those could be broken ... but you'll need to remove the transmission and disassemble to know for sure.

    I expect if you don't find something obviously broken with the transmission apart, you are going to have to condemn the synchro assembly and replace it. You'll want to get a small parts kit, new blocking rings, and maybe a new front main bearing too. Then you'll have a rebuilt transmission.

    [​IMG]

    http://www.amazon.com/Omix-Ada-18880-14-Transmission-Synchronizer-Assembly/dp/B000FQ0BDU
     
    Last edited: Jul 24, 2015
  17. Focker

    Focker That's a terrible idea...What time? Staff Member

    Drill a small hole through the handle of the screwdriver and slip on a break away wrist lanyard.
     
  18. jossar

    jossar Member

    The transmission was new in 2012 and probably has less than 1000 miles on it so I'd be surprised if the syncro hub is worn out - unless it is defective. How would I tell if there is something wrong with the hub? I suspect the blocking ring teeth were damaged due to rubbing on the dog when it slipped forward during the little bit of time it was running to try and get it into gear. I guess I'll have pull it and check out the hub and springs and replace the blocking rings. - for peace of mind if nothing else. I recall it was a real PIA to pull it - laying on my back in the driveway w/o a lift. I thought I read somewhere pulling the engine and tranny is easier than tranny and transfer case?
     
  19. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Yes, you're going to have to pull it and take it apart.

    If you have a cherry picker, you can remove the front clip and pull everything at once. The F134 is heavy, so get a good, sturdy hoist. If it were me, I'd raise the Jeep with my jack stands and pull it from underneath. You don't really need to raise the car, but a little extra room will help. If you prop up the back of the engine, you can pull the transfer case and transmission separately or a unit. In the past, I've done this with muscle. Today I have a floor jack, which I think I'd use to remove the cross member, transfer case and transmission together.