Jeep TH400's

Discussion in 'Jeeps with the Buick Heartbeat' started by 83Stage1, Sep 5, 2010.

  1. 83Stage1

    83Stage1 Well-Known Member

    Welcome Jeep guys (and gals!)

    How about a quick lesson in the TH400's used in the Jeeps? I know enough to know I don't know enough...:grin:

    I've heard that trans is basically the old nailhead case & uses an adapter to mate up to whichever engine was used? Is this correct? I have a 401 I'd like to be mating to a 4x4 capable trans...
  2. wkillgs

    wkillgs Gold Level Contributor

  3. Poppaluv

    Poppaluv I CALL WINNERS!!!

    Greg, join the International Full size Jeep Org. . Nice board , just like this one. :beer Recently got Brandy a 88' G. Wag and they have done it all. Just like these guys.:TU: I myself am looking forward to the day when I slip in a Buick 350!!!!!!! Gonna need lotsa help!!!:shock:
  4. Ristow

    Ristow New Member

    it was up to about '74. then an AMC bell'd transmission case was used. all the buick power jeeps used the nailhead w/adapter.
  5. swampedge

    swampedge Well-Known Member

    Ristows right. The Jeep t-400 is a bolt in on a nailhead. They were nail head patterned with the Buick engines until AMC bought them out and they slid there 360 into them in '71.
  6. 455jeepster

    455jeepster Member

    im trying to replace the oddfire with a 430. the install went great, but the flexplate on the 430 is hitting the adapter on the th400 trans. I put the v6 flexplat in and it fits great, but the bolt pattern is different on the flexplate. I am a bit lost. doesnt seam like the starter for the 430 wants to fit in the adapter, but its close and with a BFH I probably could get it in. fits great with the v6 flesplate, but cant tell if the teeth wil engage. Im sure a million people know what I am dealing with, but having a hard time finding any info.
  7. N360LL

    N360LL milehi71Stage1

    To recap. You have mated the '68 430 to a Jeep TH400- correct? And have had issues getting the flexplate and torque converter to mesh properly-correct?

    You have changed out the flexplate to a V6 Buick- correct? Here come the questions:

    1) What it the tag code on the transmission?
    2) What diameter is each flexplate?
    3) What is the tooth count on each flexplate?
    4) Do the bolt patterns on each flexplate match the crankshaft?
    5) What is the pilot to torque converter snout clearance?
    6) How much end play is there with the torque converter fully seated in the front pump of the transmission?
    7) Which starter are you trying to use? BBB, SBB or AMC/Jeep?
    8) Are you using a "midplate" from a AMC application?
    9) Are you mocking this up on the floor or in the vehicle?

    These are the questions I can think of at the moment. Be careful with the BH, you could cause irrepairable damage to the transmission or engine.
  8. 26Troadster

    26Troadster Well-Known Member

    we (as me and a couple of friends) have pulled the amc v8's out of jeeps and they had the amc v8 with a adaptor plate with the bop pattern, there are afew fellas in alamo amc that had this setup, one even has a bop power glide in his rambler behind a 401. didn't know about the nailhead plate will have to check that out.

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