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SM420 bolts

Discussion in '40- & 55-Series Tech' started by Bobsbash, Oct 15, 2003.

  1. Bobsbash

    Bobsbash

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    I'm trying to figure out what size bolt and thread are on the bottom of the sm420 that hold it to the bellhousing. Any help is appreciated. Bob
     
  2. bsilva132

    bsilva132

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  3. Poser

    Poser Oh...Durka Durka Durka. s-Moderator Supporting Vendor

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    [quote author=Bobsbash link=board=1;threadid=6361;start=msg51318#msg51318 date=1066257450]
    I'm trying to figure out what size bolt and thread are on the bottom of the sm420 that hold it to the bellhousing. Any help is appreciated. Bob
    [/quote]


    This is a .50 diameter bolt-13 threads per inch, about 1.5" or 1.75" in length. Remember, this is an American transmission, so any holes on the tranny should be ASE, and the fasteners should be ASE. The top bolts that thread into the Toyota three speed bellhousing through the mounting ears on the transmission are 18mm diameter x 1.5mm threads per inch, about 35 or 40 mm in length, assuming that this is going in behind a Toyota engine.

    What engine are you running?
     
  4. Poser

    Poser Oh...Durka Durka Durka. s-Moderator Supporting Vendor

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    [quote author=bsilva132 link=board=1;threadid=6361;start=msg51331#msg51331 date=1066258407]
    http://members.cox.net/cglabe1/SM420/sm420.html
    It says what size in the write up.
    [/quote]

    The only thing that I see in reference to mounting hardwear is the quote that the four speed bolts, which are metric fine thread, do not thread into the coarse thread holes in the three speed bellhousing, and to use an ASE bolt in a metric hole...Don't think I would do that, but whatever "works" I guess...
     
  5. Bobsbash

    Bobsbash

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    Thanks for the info Poser. That was exactly what I was looking for. I am running a Chevy 350 with the sm420 and stock t-case with an AA to mesh it up. I have the bolts that go into the bellhousing through the trani to hold the trani on but they didn't seem to be the same bolts for the bottom of the trani. Thanks again. Bob