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TH400 Question

Discussion in 'The Garage' started by Smitty, Dec 7, 2003.

  1. Smitty

    Smitty 1/2 ton status

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    Is there any difference in the TH400 found behind a 6.2 and one behind a small block? Checking to see if they're direct swaps. Might be a dumb question but I don't have the two together to compare.

    Smitty
     
  2. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

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    The tranny will swap, not sure if there are any internal differences though.
     
  3. 84_Chevy_K10

    84_Chevy_K10 Banned

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    [ QUOTE ]
    The tranny will swap, not sure if there are any internal differences though.

    [/ QUOTE ]

    Not really, but the TC stall speed is much lower IIRC.
     
  4. bigred81

    bigred81 1/2 ton status

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    The transmission is the same but the torque convertor has a different stall speed. I ran in to this when I went with a big block in my brother truck. We ended up putting in the torque convertor for the big block so that we would not ruin his freshly rebuilt th400. The th 400 torque convertor from a 350 motor would hook up faster but you run the risk of blowing up the torque convertor behind a diesel and a diesel torque convertor is build to take the torque that a diesel produces at low rpm. To answer your question yes it is a direct swap in. Hope this helps you without confusing you.

    James Startz
     
  5. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

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    [ QUOTE ]
    I don't have the two together to compare

    [/ QUOTE ]

    You cannot compare the stall speed of the TC just by looking at them so I am sure he wanted to know if the trans will physically bolt up.
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

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    Typically a diesel will have much lower shift points than a gas version as well. This is done with the governor.
     
  7. dhdescender

    dhdescender 1/2 ton status

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    Yeah, a stock Gas Torque converter behind a diesel is a little bit risky, its not meant to take the torque the diesel puts out. Vise vera however, diesel torque behind a gas motor will work fine if your motor has the power to fight the lower stall speed of the converter.

    I'm running a 1400-1800rpm Stall 540-3 Severe Duty Allison converter with my Th400. This gets me machined splines, solid steel stator, and brazed fins. In other words, one kickass torque converter meant for a 5 ton.
     
  8. boz42

    boz42 1/2 ton status GMOTM Winner

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    not trying to high-jack, but i thought diesel engines had BOP bell housing patern?
     
  9. Smitty

    Smitty 1/2 ton status

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    Want to thank everyone for the info. I was planning on going with an aftermarket torque convertor so it shouldn't be an issue. If I replace the gov will it eliminate the problem of different shift points or is there any other mechanism that will need to be replaced/adjusted?
     
  10. dhdescender

    dhdescender 1/2 ton status

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    No, only the only 5.7L olds diesels did. 6.2's and 6.5's are a chevy block.
     
  11. dyeager535

    dyeager535 1 ton status Premium Member

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    I think the governor is all that needs to be adjusted. You can buy governor recalibration kits to retune your shift points.

    Not sure if all TH400's use the same drive gear for the governors, if they do, then you could just swap in your old one (if you have one) and be done with shift points.

    You can buy adjustable modulators, but at WOT, the difference between the two extremes of the adjustment was a whopping 5MPH, hardly worth it.
     

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