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T15 / T150 Compatibility (or T15 Top Cover Wanted)

Discussion in 'Intermediate CJ-5/6/7/8' started by Lane Meyer, May 21, 2020.

  1. May 21, 2020
    Lane Meyer

    Lane Meyer New Member

    Maryland
    Joined:
    Apr 23, 2019
    Messages:
    21
    Good morning!

    I removed my T15 for rebuild and found that the top cover was broken. I found a replacement but my friends at the USPS seem to have misplaced it for the last couple of weeks. As I start to accept the reality that it may not turn up, I'm looking at other options. My first choice would be to find a good T15 top cover since I have already purchased rebuild parts for my T15.

    There is a T150 available locally which is priced cheap. I'm starting to look at it as a possible replacement option. My intended use doesn't require a low-first four speed or anything bomb-proof - mild off-road (forest roads & beach) and runs into town for ice cream mostly.

    Anyway, I'm not a transmission expert by any definition. I'm looking at Novak's site and comparing info and could use some help deciphering. I've pasted the relevant info for the T15 and T150 transmissions below. The difference in length and the difference in input shaft suggest that it is not a direct bolt-in swap with no other mods. Can anyone confirm? The input shaft differences jump out at me as being a problem.

    Thanks for any input/insight!

    T150
    The T150 transmission is 9" (or 9.25” per the “at a glance” image) long and features a cast iron top cover that is retained by eight bolts.

    The Jeep T150 has a 1-3/8" x 6 spline output shaft for mounting the transfer case input gear. The transmission has a 7-1/2" input shaft (stick-out length) with 1-1/16" x 10 splines and a neoprene front seal and cast iron bearing retainer. The pilot tip is ~17mm.

    Gearing: 2.99, 1.75, 1.0, Rev. 3.17

    T15
    The T15 transmission is 10" long and features a cast iron top cover that is retained by 8 bolts.

    The Jeep CJ T15 had a 1-1/8" x 10 spline input shaft (or "clutch shaft") with an ~8-1/2" stick-out length and its pilot tip is ~3/4" in diameter.

    The T15 transmissions as found in Jeeps has a 1-3/8" x 6 spline output shaft for mounting the transfer case input gear.


    Gearing: 3.00, 1.83, 1.0, Rev. 3.00.
     
  2. May 21, 2020
    oldtime

    oldtime oldtime

    St. Charles,...
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    Aug 14, 2006
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    2,757
    I have found that on occasion usps will misplace and find stuff two weeks late. So don’t give up too soon.
    I do recall that the Tremec 150 and the BW T15 have very different bell bolt patterns. And the 1” difference in length issue must also be addressed . The input spline diameter is easy to circumvent via the driven disk. But the clutch fork and or bearing carrier might also become an issue.
     
  3. May 21, 2020
    Lane Meyer

    Lane Meyer New Member

    Maryland
    Joined:
    Apr 23, 2019
    Messages:
    21
    Thanks for the quick reply. Sometimes you just need a tap on the side of the head with reality. :) If I'm going to do anything other than direct bolt up/easy swap, I'll look for a four speed.

    Hopefully the USPS will come through. It has "only" been a couple of weeks.
     
  4. May 21, 2020
    timgr

    timgr Jeepin' Nerd 2020 Sponsor 2019 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
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    20,893
    The T-150 is a Ford passenger car 3-speed transmission, made on license for Jeep by Tremec. The T-15 is a Borg-Warner transmission, and their design. Lots of differences, and interchange only with a lot of different parts. The front pattern and bell housings are different, and the T-150 bell housing is shallower, along with the case length being shorter. This means the transmission position moves forward, along with the transfer case and all the adjustments that entails. The T-150 is also not as strong as the T-15. Not bad, but considered a step down from the T-15.

    How is the old shift top broken? A skilled welder may be able to repair it. If not, I expect that finding a shift top on its own will be difficult. Possible you could locate another core transmission, take what you need and eBay the gears. T-15s were also used in Wagoneers and J-trucks, and their shift tops will be compatible with yours - post a WTB on the Wagoneer forums. You might also try Herm the Overdrive Guy, since he sells these transmission rebuilt and may have more cores with shift tops than he needs, and be willing to part with one.
     
    Last edited: May 21, 2020
  5. May 21, 2020
    oldtime

    oldtime oldtime

    St. Charles,...
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    Come to think of it I got involved with a local guy who went the other way around. I sold him a T15 because someone had managed to put a T150 into his 1975 cj-5. I’m pretty sure he also had to locate a proper bellhousing, etc.
    From what I recall the T150 was a very poor fit since it also messed up the locations for his shift levers.
    He was much more than happy to get the T15.
    So happy that he gave me the T150 for helping him out.
    And of course I just ended up selling the T150 to a guy with a later cj.
     
  6. May 21, 2020
    nickmil

    nickmil In mothballs.

    Happy Valley, OR
    Joined:
    Sep 23, 2002
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    11,565
    The T-15 is the strongest 3 speed transmission Jeepused. The T-150 is “ok” but not something I’d convert from a T-15 for. Bell housing is different, overall length is different, clutch disk is different, pilot bearing is different, input length is different, transfer case input gear is different, shifter location is different, driveshaft length is different. Not a direct replacement. He used to have a bunch but not sure if he still does but might contact Richard at 503-557-8911. I think he is out of town this weekend though. I’d wait a bit though as mentioned and see if yours shows up.
     
  7. May 22, 2020
    Lane Meyer

    Lane Meyer New Member

    Maryland
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    Apr 23, 2019
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    I foolishly assumed that the T150 was an evolution of the T15 given that it followed in CJs. :) The boss that holds one of the shift rails is broken - I believe I posted a pic in an earlier thread. Unfortunately repair isn't a practical option.
     
  8. May 22, 2020
    Lane Meyer

    Lane Meyer New Member

    Maryland
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    Yeah - pretty clear that going T15 --> T150 is not a good option. I foolishly assumed that the T150 was an evolution of the T15 and would be a simple bolt-in affair. If I have to do any adapting, it won't be for an inferior trans. :)
     
  9. May 22, 2020
    timgr

    timgr Jeepin' Nerd 2020 Sponsor 2019 Sponsor

    Medford Mass USA
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    You are not the first to incorrectly assume this. Likely no more than a coincidental numeric similarity.

    I found the picture in your earlier thread. Unfortunately the picture is small, so you can't see much. The forum will accept your full-size pictures by drag-and-drop. I find that 640x400 or 800x600 is a good size for posting.

    These shift tops are not hard to take apart and put together. You might take it apart and take it to a welder for a consult. Still probably cheaper to buy a whole core transmission if you can find one near you.

    I'd try Nick's suggestion of Richard first, once you have thoroughly given up on the USPS.
     
    Last edited: May 22, 2020
  10. May 22, 2020
    Lane Meyer

    Lane Meyer New Member

    Maryland
    Joined:
    Apr 23, 2019
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    Thanks Tim! As of last night, I have a little bit more time to wait on the USPS. I pulled the end main bearing cap to replace the rear main seal while the motor is out and found more bearing wear than I'd like. I'll be digging deeper to decide how far I want to go on that front. Of course, the old RMS didn't leak - it just seemed silly to not change it while the motor was out and on a stand. I should learn to let sleeping dogs lie...

    Trying to upload a better pic of the broken cover now. Unfortunately, the missing piece did not stay intact as it spent time in the transmission case. There's one piece left that accounts for about 75% of the missing metal and the rest is gone. Likely flushed out in prior fluid changes.

    transcover.jpg
     
  11. May 22, 2020
    oldtime

    oldtime oldtime

    St. Charles,...
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    I’m a welder and I would consider that to be repairable.
    Will only require some basic machine work after some metal is added.
    The tolerances are not critical.
     
  12. May 22, 2020
    Lane Meyer

    Lane Meyer New Member

    Maryland
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    I'm not sure that you'd have access to get something in to machine the bore, but I wasn't even considering that as an option last time it was in my hands. I'll take another look. I have no idea how long it was broken. The shift fork does a good job of supporting the shift rail and it shifted just fine.
     
  13. May 22, 2020
    Oldriginal86

    Oldriginal86 Member

    Pasadena, Md.
    Joined:
    Nov 5, 2014
    Messages:
    503
    That boss main job is to hold the detent spring and ball correct? Support is on either end. Maybe do nothing. Is that an option?
     
  14. May 22, 2020
    Rich M.

    Rich M. Shoe pusher

    Maryland
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    Mar 23, 2008
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    734
  15. May 22, 2020
    Lane Meyer

    Lane Meyer New Member

    Maryland
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    Apr 23, 2019
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  16. May 22, 2020
    Lane Meyer

    Lane Meyer New Member

    Maryland
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    Apr 23, 2019
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    I have considered that option for sure. Doing nothing is one of my core competencies.
     

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