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T90c Reverse Idler?

Discussion in 'Early CJ-5 and CJ-6 Tech' started by fyrmn, Jan 1, 2019.

  1. Jan 1, 2019
    fyrmn

    fyrmn Sponsor Sponsor

    Camp Verde, AZ
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    Apr 29, 2006
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    76
    my t90c has a 15 tooth reverse idler. Is this another unique gear associated with the t90c? I was going to replace it due to minor pitting. Thought I read that the 16 tooth will work also. ????
     
  2. Jan 1, 2019
    timgr

    timgr Jeepin' Nerd Sponsor

    Medford Mass USA
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    Change in tooth count will change the ratio. I'm going to predict with 99% certainty that you can't do that.
     
    wheelie and Rick Whitson like this.
  3. Jan 1, 2019
    Rick Whitson

    Rick Whitson Detroit Area Sponsor

    I live South of...
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    Like Tim says, everything has to match to the cluster, input shaft and the sliding gears as one unit. My FSM shows the different ratios for different transmissions, the T 90 column shift, and the T 90 floor shift have different ratios, but you can't mix them. Good Luck
     
  4. Jan 1, 2019
    Mcruff

    Mcruff Earlycj5 Machinist Sponsor

    Albertville, AL
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    Tooth count will change diameter, not a chance it will fit unless the mating gear is changed.
     
  5. Jan 2, 2019
    oldtime

    oldtime oldtime

    St. Charles,...
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    The 16 tooth gear is the correct one for all T90 transmissions.
    Your 15 tooth gear must be from something other than a T90
     
  6. Jan 2, 2019
    Howard Eisenhauer

    Howard Eisenhauer Super Moderator Staff Member Sponsor

    Tantallon, Nova...
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    IMHO minor pitting is not cause for replacement.
     
  7. Jan 2, 2019
    fyrmn

    fyrmn Sponsor Sponsor

    Camp Verde, AZ
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    IMG_2294.JPG Thanks Howard! I'll probably let it be. So far I cant source a 15 tooth idler.

    Oldtime: all I know is the cluster is the 35 tooth version which I believe is a T90c perhaps that is why the idler us a 15??? I am no expert but this is what was in there when I removed it.
    Along with this tag. Case "T90A-1" Thanks to all who replied!
     
  8. Jan 3, 2019
    oldtime

    oldtime oldtime

    St. Charles,...
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    Jeep T90 A and Jeep T90 C use the exact same reverse gear.
    Maybe it's the reverse idler from a T86AA ?
    I don't have any T86 transmissions but could check to see if the part numbers are different....

    AFAIK It's' also feasible that it came from something like a Studebaker or IH version of the T90.
     
  9. Jan 3, 2019
    Tomellen

    Tomellen Member

    Ticonderoga, NY
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    Sep 16, 2016
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    I just tore down a T86 aa transmission so I checked that ider gear. It is a 15 tooth gear. Counted it 3 times.
     
  10. Jan 13, 2019
    fyrmn

    fyrmn Sponsor Sponsor

    Camp Verde, AZ
    Joined:
    Apr 29, 2006
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    Interesting, From Novavks site:
    "T90's were produced with 16 tooth reverse idler gears up to 1965. Models afterward were produced with 15. "

    Since I don't know the history of this jeep, all I can say is it had the 35 tooth cluster and a 15 tooth reverse idler.

    Shout out to Pete Debella. Purchased all NOS
    9-1/4 clutch kit
    35 tooth T90 cluster
    Reverse idler gears
    Great quality!
     
    Twin2 likes this.

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