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400/208 adapter needed...got one?

Discussion in 'The Garage' started by jones, May 24, 2004.

  1. jones

    jones 1/2 ton status

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    if anyone could help me out on this one,i'd sure appreciate it.i'm in desperate need of an adapter.the one i have is too thick.(see"drive shaft length"post by jones on p.5)have 4",need 2".PLEEESE /forums/images/graemlins/1zhelp.gifi'm almost to the point of chopping it w/ a chop saw,cutting an inch off each half,then welding it back together. /forums/images/graemlins/thinking.gifHEY!thats not really aload bearing point,so would that actually work? /forums/images/graemlins/dunno.gifwhat else to do.cash flow barely exists. /forums/images/graemlins/frown.gif /forums/images/graemlins/1zhelp.gif
     
  2. 84_Chevy_K10

    84_Chevy_K10 Banned

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    You need to get the correct driveshafts. You can't just shorten the adapter.
     
  3. big83chevy4x4

    big83chevy4x4 3/4 ton status

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    you are trying to put a th400/208 inplace of a 700r4/208, right? do you have a th400/208 assembly or are you gonna use the 208 and adapter from the 700r4 on the th400? if you are trying to use the 70r4 version 208 and adapter on the th400, it wont work.
    1, the bolt pattern for the back of the tranny is different between the th400 (6 bolt) and the 700r4 (4 bolt)
    2, the input splines on the 208 is different, the 700r4 is 27 spline and the th400 is 32 spline.

    every adapter for the same tranny hooking to the same tcase will always be the same thickness, gm never changed them. if you cut 2" from the adapter you will also have to cut 2" from the output shaft on the tranny, then you may not have enough spline enguagement in the tcase and you will destroy the output shaft and the tcase.

    if you don't have the th400 version adapter and 208, try wandels. they have tons of chevys last time i was out there. im sure you could find a few adapters and tcases. /forums/images/graemlins/waytogo.gif
     
  4. 83ZZ502_Jimmy

    83ZZ502_Jimmy 1/2 ton status

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    A 400/208 is the same length as a 700R4/208 combo. The adapter makes the difference. Its a 1/2" thinner. I've done the swap on 3 different trucks.

    Driveshafts will be unaffected. Check the local junkyards for it. It is a fairly common piece.
     
  5. Mastiff

    Mastiff 1/2 ton status Premium Member

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    Advance Adapters has what I think you're talking about. My truck has a 400 put in place of a 700R4 and that's what I used.
     
  6. jones

    jones 1/2 ton status

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    i do have the 400/208 assembly but there is only .25"-.5" engagement because the adapter is so thick.i thought if the adapter could be cut 2",it would allow full engagement.it kinda makes sense to me.the 400 has 2.25"shaft.w/.25" engagement.cut 2",bring both halves together to complete the engagement.should work,in theory,but i'm no Einstein,either.i'll try Wandel's anyway.Attn.big83chevy4x4:theres an older dude that lives just south of COUNTY FARM RD.past the lake,toward the curves,on ???RD.can,t remember the name of the RD.know where i'm talkin about?ever been there?
     
  7. 83ZZ502_Jimmy

    83ZZ502_Jimmy 1/2 ton status

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    Sounds like you have a TH400 for a 203 case.

    The 203 is the shortest shaft, followed by the 208 then 205.

    John
     
  8. big83chevy4x4

    big83chevy4x4 3/4 ton status

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    you mean Maguires 4wd junkyard? been there once. he's just off derbty road.

    i ran into him a few months ago any he said he got rid of most of his stuff, then his wife left him and he started his shop back up again, not sure what he has now.
     
  9. u2slow

    u2slow 1/2 ton status

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    [ QUOTE ]
    Sounds like you have a TH400 for a 203 case.


    [/ QUOTE ]

    My thoughts exactly. /forums/images/graemlins/thinking.gif

    I see three ways around this:

    1. Get the right length output shaft
    2. Get another TH400 with the right shaft
    3. Run an NP203 instead (good for Doubler later on /forums/images/graemlins/wink.gif )
     
  10. doctor4x4

    doctor4x4 1/2 ton status

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    EXACTLY WHAT U2 Said :-)
     
  11. jones

    jones 1/2 ton status

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    BAD NEWS!tranny shop call this morning,said the rear sprag is blown out and asked if i could find another core w/ good,hard(not broken)parts. /forums/images/graemlins/frown.gif$6-700 to rebuild,replacing everything.told him for that price i might as well have the 700 rebuilt HD style then i wouldn't have to screw with the conversion.he agreed.then i got to thinking about bow-tieOD.stage 1 for $866.has anyone ever ran a bowtieOD trans?what did you think?
     
  12. big83chevy4x4

    big83chevy4x4 3/4 ton status

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    where did you take the tranny? 6-700 is not that bad for a TH400.
    what did he tell you on the 700r4?
     
  13. jones

    jones 1/2 ton status

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    john wing at Ionia Transmissions.$6-700 includes the torque converter,too!he quoted $750 to rebuild the 700.rebuilds are guaranteed(60 days,i think he said)and all include torque converters.John Wing owns the place but a younger guy,Nick ?,does the work and give quotes.i haven't had any work done by him yet but plan on having him do it.write it down...616-527-1619.m66 S.to DAVID HWY,THEN L.(EAST)MAYBE 300 YDS.ON R.SIDE.
     
  14. 84_Chevy_K10

    84_Chevy_K10 Banned

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    [ QUOTE ]
    where did you take the tranny? 6-700 is not that bad for a TH400.

    [/ QUOTE ]

    That is over twice what I payed. That is far too much if you ask me, unless you're talking about upgrades.
     
  15. jones

    jones 1/2 ton status

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    [ QUOTE ]
    [ QUOTE ]
    where did you take the tranny? 6-700 is not that bad for a TH400.

    [/ QUOTE ]

    That is over twice what I payed. That is far too much if you ask me, unless you're talking about upgrades.

    [/ QUOTE ]thats talking all new everything on the insude of the th400 plus torque converter.
     

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