1. Registration trouble? Please use the "Contact Us" link at the bottom right corner of the page and your issue will be resolved.
    Dismiss Notice

Transmission/T-case Swap

Discussion in 'Early CJ5 and CJ6 Tech' started by Peter Harman, Apr 29, 2018.

  1. May 7, 2018
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    23,596
    Prior to 1971, Jeep used a GM BOP (Buick-Olds-Pontiac) bell housing with the 225. This was combined with a long input shaft and adapter to mate to the T-86 or T-14. Typically Jeep would stock the GM parts used in their cars under the GM part number, so it's essentially a GM bell. Same part.
     
  2. May 7, 2018
    71CJ54WD

    71CJ54WD Sponsor

    DC
    Joined:
    May 3, 2018
    Messages:
    356
    Thats great news - one of the few times a Man hopes to have the shortest of something.
     
  3. May 7, 2018
    mike starck

    mike starck Member

    salem,oregon
    Joined:
    Jun 22, 2006
    Messages:
    762
    The jeep version of the BOP bell has a left hand starter bulge deleted and the part number cast in that section. I have sold a few BOP bells with the starter bulge on both sides and it really doesn't effect the use on a jeep.But if your going 100% correct you will pay more for the jeep version usually.
     
  4. May 7, 2018
    colojeepguy

    colojeepguy Colorado Springs

    At the foot of...
    Joined:
    Apr 4, 2010
    Messages:
    7,110
    :lol:
    If you have the stock 1971 bellhousing, it won't work. The 66-70 V6's used a standard GM bellhousing with an adapter plate as mentioned above but in 71 they went to a one piece unit with no adapter.
     
  5. May 7, 2018
    Twin2

    Twin2 not him 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Virginia Beach, VA
    Joined:
    Apr 28, 2011
    Messages:
    5,407
    one other note . the BOP bell housing double hump . doesn't play well with the frame mounted master cylinder
     
    mike starck likes this.
  6. May 7, 2018
    y2grey

    y2grey Member

    Fayetteville NY
    Joined:
    Sep 18, 2011
    Messages:
    106
    The ford t18 can be mated to the GM BOP bell housing without an adapter by some re-drilling and machine work etc. it will be the shortest combo. The 77-79 jeep t18 requires a 1 inch adapter plate to take up the extra input shaft length if you don't want to change out the shaft.
     
  7. May 7, 2018
    71CJ54WD

    71CJ54WD Sponsor

    DC
    Joined:
    May 3, 2018
    Messages:
    356
    Sorry what won't work?
     
  8. May 7, 2018
    71CJ54WD

    71CJ54WD Sponsor

    DC
    Joined:
    May 3, 2018
    Messages:
    356
    Yeah the trans should mate right up with some minor modifications to the T18.
     
  9. May 7, 2018
    colojeepguy

    colojeepguy Colorado Springs

    At the foot of...
    Joined:
    Apr 4, 2010
    Messages:
    7,110
    The T18 won't work with the 1971 bellhousing
     
  10. May 8, 2018
    71CJ54WD

    71CJ54WD Sponsor

    DC
    Joined:
    May 3, 2018
    Messages:
    356
    Thanks for telling me. Would have been a bear to get under there and wrestle a T18 for 3 hours only to wonder why it won't fit :lol:

    Any idea if my current bell can be modified to work with the T18 or do I need a 70 and older bell? What would be the shortest years and models for the bells if I have to go hunting?
     
  11. May 8, 2018
    colojeepguy

    colojeepguy Colorado Springs

    At the foot of...
    Joined:
    Apr 4, 2010
    Messages:
    7,110
    You need the 66-70 version
     
    71CJ54WD likes this.
  12. May 8, 2018
    71CJ54WD

    71CJ54WD Sponsor

    DC
    Joined:
    May 3, 2018
    Messages:
    356
    Is there an adapter that is a separate piece of the 66-70 bell that I should be getting with the bellhousing?
     
  13. May 8, 2018
    Warloch

    Warloch Did you say Flattie??? Staff Member

    Falcon, CO
    Joined:
    Mar 4, 2003
    Messages:
    5,466
    No - you just need the older BH - the Adapter is only needed if your using a T90/T86.

    You can also look at Novak and AA. They offer some BH with the work already done to them. I got one for the SM465 machined and ready to go the first time I did one so I knew what to do from there forward.
     
    71CJ54WD likes this.
  14. May 8, 2018
    71CJ54WD

    71CJ54WD Sponsor

    DC
    Joined:
    May 3, 2018
    Messages:
    356
    I see advance adapters has a bell I could use. As long as the stock bell and the T18 input length work I don't mind the work thats required to the T18 to make it mate. From what I see on the Novak site the stock non-71 bell and the Ford T18 will work.
     
  15. May 9, 2018
    Warloch

    Warloch Did you say Flattie??? Staff Member

    Falcon, CO
    Joined:
    Mar 4, 2003
    Messages:
    5,466
    Correct - my process was to modify the T18 case and bearing retainer. Used the Ford input and Jeep output w/plate - did a rebuild on the tranny while swapping the parts.
     
    Bowbender and 71CJ54WD like this.
  16. May 10, 2018
    Peter Harman

    Peter Harman New Member

    Fountain CO
    Joined:
    Feb 4, 2018
    Messages:
    33
    Waaaaait a minute... I see what you did there! (y)
     
  17. May 10, 2018
    Norcal69

    Norcal69 Out of the box thinker 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Northern California
    Joined:
    Sep 6, 2014
    Messages:
    3,548
  18. May 10, 2018
    71CJ54WD

    71CJ54WD Sponsor

    DC
    Joined:
    May 3, 2018
    Messages:
    356
  19. May 13, 2018
    whateverpratt

    whateverpratt New Member

    Deltona, FL
    Joined:
    Oct 4, 2017
    Messages:
    38
    I've been contemplating a 4 speed swap for the future as well, but I haven't been able to decide between the sm420, sm465, or the t18. Does anyone have the lengths of these different transmissions mated to a dana18? My first thought was the sm420 because I think it will bolt right up to the buick bellhousing, but then I saw the sm465 adapter was only 1 inch long. Now I'm wondering if a frankenstein t18 would be the best option
     
  20. May 13, 2018
    timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Medford Mass USA
    Joined:
    Aug 10, 2003
    Messages:
    23,596
    I believe Novak gives you that information on their site. Novak Conversions Home

    The two GM Muncie transmissions (SM420, SM465) will bolt up to a GM bell without modification (mostly). The Ford transmissions (T-18. T-19, NP435) will bolt up to a GM bell with minor machining. Novak covers all of this on their site - just keep following the embedded links on their site and you will cover the issue completely.
     
New Posts