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Clutch Or Transmission?

Discussion in 'Early CJ5 and CJ6 Tech' started by jeepstar, Sep 28, 2021.

  1. Sep 28, 2021
    jeepstar

    jeepstar Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Sheboygan
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    62 cj5, 134 motor with a t90.
    I put a new clutch in last year, it worked. now, its sloppy, and grinds if go 1 to R, or N to 1/R. I can start it in 2, shift to 3 no problem when driving.
    I shut the jeep off to go to reverse, or 1st if I'm in the woods going too slow for 2nd.

    clutch is adjusted, no slop in pedal. I can try and tighten it up more.

    my thought is the trans is just worn out that bad? it pops out of gear when driving upon deceleration.

    I dont know anymore....hope you guys do?
     
  2. Sep 28, 2021
    colojeepguy

    colojeepguy Colorado Springs

    At the foot of...
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    Sounds like 2 problems. Clutch isn't releasing fully (grinding into 1st) and trans is worn (popping out of gear).
     
  3. Sep 28, 2021
    jackdog

    jackdog Member

    Finger Lakes NY
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    X2. Popping out of gear usually means synchro rings are worn. If the clutch isn't releasing fully it will grind going into 1/R. The T90 has an unsynchronized 1st gear.
     
  4. Sep 28, 2021
    jeepstar

    jeepstar Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    clutch isnt releasing fully means i should tighten the cable more?

    are both problems related to one another?
     
  5. Sep 28, 2021
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
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    As I understand it, popping out of gear on decelleration usually means the bushing inside second gear is worn out. The gear sits on the main shaft and rotates on the oil film. When worn out, the bushing allows the gear to skew on the shaft, pushing the synchro hub away from the gear and slipping off. This is more likely than the synchro hub being worn, which is also possible.

    New second gears (with a new bushing) are available for the T-90.
     
    jackdog likes this.
  6. Sep 28, 2021
    Oldpappy

    Oldpappy A.C. Fults - Curmudgeon at large 2022 Sponsor

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    "clutch is adjusted, no slop in pedal"

    There is supposed to be some free play in the pedal. If the clutch is too tight it will not fully engage and will eventually begin to slip, but that isn't what is causing your shifting problems. As said above, worn out synchronizer or 2nd gear bushing is likely the culprit.
     
  7. Sep 28, 2021
    jeepstar

    jeepstar Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    my gut tells me it's the transmission causing the grinding, because I can shift from 3 to 2, and 2 to 3 with no problem. there is no clutch slippage. and I've known for over a year about the popping out of gear problem.

    I should add, I'm not a mechanic and have no formal training.
     
  8. Sep 28, 2021
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

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    Seems very unlikely. Unless you've got something seriously wrong, like the front main bearing seriously worn out. I'd think you'd hear that distinctly. Especially the 1st-reverse clash at idle, that seems like a clutch problem. The popping out of gear comes from worn parts in the transmission.

    I'm sure you realize that you need to let the gears spin down before you shift into 1st or reverse. At a standstill, depressing the clutch pedal should disconnect the clutch disk and thereby the transmission main shaft from the engine, and everything rear of the clutch cover stops. If these gears clash no matter how long you hold the clutch in, it means the main shaft is continuing to spin regardless of the clutch position. This seems rather definite as a clutch problem.

    If the clutch disconnects mostly, you should still be able to shift into second or third. The 2 and 3 blocking rings have enough friction to overcome the speed of the main shaft if it's loosely coupled to the engine. Bad for the blocking rings, but they are essentially little clutches.
     
    jeepstar likes this.
  9. Sep 28, 2021
    jeepstar

    jeepstar Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    its needs to be tightened or loosened? rpm is down at idle, I know I cant have higher rpms at the downshifting and reverse shifting.
     
  10. Sep 28, 2021
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

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    I don't think more slack will help, but it's an easy test in either direction. I suspect you can't adjust away this problem, if you already have like an inch or less of easy travel at the top of the clutch pedal travel. There should be an obvious point in the clutch pedal travel where the throwout bearing contacts the pressure plate. Prior to that, it's just the linkage return springs that you work against. Once the TO bearing is up against the cover plate fingers, the TO bearing must compress the springs in the clutch cover to travel any further. Much much harder. It should be obvious as you move the pedal.
     
  11. Sep 28, 2021
    jeepstar

    jeepstar Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    not for me.... I have to remove the whole transmission tunnel cover inside the Jeep to adjust the cable. There's no room for me underneath. I did the Metcalf disk conversion and put in a dual master cylinder at this time and I also had to set the exhaust down that route as well so I cannot adjust it from the underside.
     
  12. Sep 28, 2021
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

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    Can't help with that.
     
  13. Sep 28, 2021
    jeepstar

    jeepstar Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    but...why not? thanks for taking the time to respond at all.

    :beer:
     
  14. Sep 28, 2021
    Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

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    Do you drive the jeep much? Could be things have formed a bit of surface rust & are getting a little grabby, going through that with Tonk right now.
     
  15. Sep 28, 2021
    jeepstar

    jeepstar Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    haven't drove it since February, lost any interest in it. starting to warm back up to it though. other than starting it to move around my shed, it's been sitting. I drove it to a mechanic to get the new tires on last week. wife's been wanting to drive her jeep so I don't sell it on her. I'm just trying to make it safe and reliable for her to drive on the street to and from work.
     
  16. Sep 28, 2021
    jeepstar

    jeepstar Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

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    it was the clutch. spent a few hours to adjust it back 1/4". floors back together and it's fine for shifting into any gear, up or down, forward or backwards.
     
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  17. Sep 28, 2021
    Keys5a

    Keys5a Sponsor

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    Glad you got the main issue taken care of. The jumping out of 2nd gear is a transmission issue discussed previously. The Jeep will be drivable, and may get worse over tive/use. You know about it, so just push the clutch in at time when it pops out.
    This issue can either be a bad bushing in actual 2 nd gear, or worn roller bearings on the input shaft of the transmission, or a bad pilot bearing. Any of these can cause the transmission to pop out of 2nd gear.
    -Donny
     
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  18. Nov 6, 2022
    Eric

    Eric Member

    CA
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    Can anyone recommend a source for the "slipping out of second" parts? Mine does the "slipping out of second on deceleration" dance well! :) Thanks
     
  19. Nov 6, 2022
    Oldpappy

    Oldpappy A.C. Fults - Curmudgeon at large 2022 Sponsor

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    Eric,

    Check with Sal. https://vintagejeeper.com/products-&-services

    While those parts can be replaced to help with the popping out of 2nd problem it make sense to refresh the whole transmission while you have it torn down for doing that.

    The T-90 is a simple transmission to rebuild, and I recently bought a dummy main shaft made of hard plastic from Sal's site that makes loading the roller bearings in the main cluster easy on the bench. Works better than the wooden dowels I used to use.

    It takes longer to clean everything up than it does to reassemble a T-90, and if you use that dummy shaft with small rubber bands to temporarily hold the roller bearings in place assembly is easy and quick. I got the idea for the rubber bands from a YouTube video done by Rick Stivers, who has several excellent videos and write ups on the subject.
     
    Eric likes this.
  20. Nov 6, 2022
    Keys5a

    Keys5a Sponsor

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    Like oldpappy suggests, if your going into the transmission, just go through everything while its torn open. As I posted earlier, there are three typical causes of popping out of 2nd gear on decelleration. A worn bronze bushing in the 2nd gear, worn roller bearings or mating shaft ends where the main drive (input shaft) and mainshaft fit together, or a worn pilot bushing in the back of the crankshaft. It can be any one of these items, or a combination of more than one.
    -Donny
     
    Eric likes this.
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