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4l60e unboltable bellhousing to 203/205?

Discussion in 'OffRoad Design' started by tjayandlisa, Sep 21, 2002.

  1. tjayandlisa

    tjayandlisa Registered Member

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    I am told that the output shaft can not be replaced on the unboltable bellhousing version 4l60e to be able to mount the 203/205? Is this true? If so what are my alternatives? the spacers that I have seen are for the four bolt 700r4/4l60, this is the six bolt round....help soon please, as the autotrac held up for one day wheelin, twice!
     
  2. u2slow

    u2slow 1/2 ton status

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    You're right, the 4-bolt spacer won't work, and I don't think anyone makes a different length output shaft for that tranny. The spline is the same (27) as the older TH700 or TH350.

    Look for other t-cases with electronic speedo's to swap in. NP205 and NP203 don't have this. An NP241C from a 88-98 1500 or light 2500 is probably your best bet. You can even get a slip-yoke eliminator (SYE) kit for this particular one.

    After you get the t-case, you'll just need to figure out a length for the adapter. A good machine shop should have no problems making an adapter from two bolt patterns and a length.

    Good Luck!
     
  3. willyswanter

    willyswanter 1/2 ton status GMOTM Winner

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    I believe his reasoning for wanting to bolt up the 203 is because he is planning on running a doubler.
     
  4. u2slow

    u2slow 1/2 ton status

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    For Doubler action - hmmm...

    Well, the TH350 version of the 203 will spline up to the tranny you have. You'd have to get an adapter made (two bolt patterns and a length - no biggy).

    You still need an electronic speedo. An ultra-rare '91 crewcab np205 has one, otherwise its the NP231, NP241, BW4401, or BW4407.

    I think I've heard that Painless wiring makes a speedo tranducer box to convert mechanical speedo drives to an ECM-friendly electronic pulse.
     
  5. Stephen

    Stephen 1/2 ton status Moderator Vendor

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    Not being very familiar with what you have, some of this is a guess, but here we go....
    I'd look into drilling the front face of the 203 to match up to the bolt pattern of the adapter on the back of your trans. The shaft stickout should be close to what you need, and it should be 27 spline which is right for the 350 version NP203. If this won't work, I'm stumped.
    past that, you'll need a ford 205 with the output modified to work with a speed sensor, which has been done by others here and is not a huge deal. Add new driveshafts, crossmembers, and the shifters and you're done.
    Far from a trivial conversion but maybe better than scattering transfer cases all the time.
     

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