Well I'm phukd. Th400 lost 3rd

Discussion in 'Tech Discussion' started by da_raabi, Nov 13, 2017.

  1. Jrgunn5150

    Jrgunn5150 Full Access Member

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    The only thing I'd do in way of modifications if the hard parts are good is dual feed the direct clutches. I'd do it internally while rebuilding and not via VB plate.
     
  2. da_raabi

    da_raabi Full Access Member

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    That's my plan. The Transgo 400-1-2 kit is pretty cheap on eBay. Most places list it for $90+, eBay has it for $69.
     
  3. da_raabi

    da_raabi Full Access Member

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    I was curious about that. I know you can do some internal modifications, but how would they interact with a shift kit like the one from Transgo?

    Check out the attached PDF I made of an old Jake's Performance tech article.
     

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  4. 74 Shortbed

    74 Shortbed Full Access Member

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    The Transgo kit is a "Reprogramming" kit, let's you start out in any gear and it stays there until you shift it, also let's you downshift at any speed into any gear, if that don't interest you save the money and just do the "dual feed" and drill out the feed holes and you'll have firm 1-2 and 2-3 shifts.
     
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  5. Jrgunn5150

    Jrgunn5150 Full Access Member

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    Transgo does the same thing with a plate between the VB and the case. My issue is that it can leak internally and not function properly. I prefer to just make the internal change and be done with it.

    The TH400 is dual fed with the holes drilled larger like Mike said, and is happily doing rolling 50 mph burnouts with roughly 500 whp.

    Since you're rebuilding anyway, you can make the internal changes while you're in there. REally no reason to blow the extra cash on a shift kit.
     
  6. MikeB

    MikeB Full Access Member

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    Reverse torx socket??? Those folks need to turn slowly and walk away from the project.:eek:
     
  7. MikeB

    MikeB Full Access Member

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    Just want to say I am learning a bunch here about auto transmissions. All my comments above are from a novice's perspective. As I mentioned in another thread, I'd really like to find an 1988-up 700R4 and go through it to use in my truck, but looks like that would require several expensive tools, right? I'd also be open to a 2004R, which would handle all the power I'd ever need it to.
     
  8. Honky Kong jr

    Honky Kong jr Super Sarcastic Man

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    And don’t use Dextron. My automatics get Type F and have for years.
     
  9. da_raabi

    da_raabi Full Access Member

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    What stall should I be looking at in a converter? The truck is a basically-stock 454 dually with 4.10s out back. 2wd. Would 2000 be too high? I'm trying to find a cheapie converter, but they get expensive fast when you drop below 2000.
     
  10. Jrgunn5150

    Jrgunn5150 Full Access Member

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    You can try one from a 6.2 truck, or spec'd for a 6.2 diesel for a budget low stall.
     
  11. da_raabi

    da_raabi Full Access Member

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    Well right now I'm looking at 2 different converters, both stock remans from Dacco. The first is a TH400 model with a 1200-1400 stall, the other is a TH350 model with a 1700-1900 stall. Thoughts on going to a slightly higher stall? Price is about the same on RockAuto. About $60 after core return (not bad!!).
     
  12. CSFJ

    CSFJ Magnificent Bastard Supporting Member

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    Isn't there a difference on the bolt pattern to the flex plate between the 350 and 400, or am I mis-remembering?
     
  13. da_raabi

    da_raabi Full Access Member

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    Yes, there are two different bolt patterns. I think the TH400 converters use an 11.5" (approx) pattern while the TH350 uses a 10.75" (approx) pattern. I had to deal with this when I was trying to put a TH350 behind a 454 in my Camaro. Summit sells a real nice flexplate that has both bolt patterns for about $50. Its even SFI approved and made in USA.

    I needed a new flexplate anyway since the original got chewed up by a broke-ass starter. So I can use whatever converter I want.
     
  14. CSFJ

    CSFJ Magnificent Bastard Supporting Member

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    Gotcha. Didn't know if you had the dual pattern flexplate already.
     
  15. Jrgunn5150

    Jrgunn5150 Full Access Member

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    I'd need to know the specs on your engine, cam, gear ratio, tire size, usage, before I could really get into pro's and cons of each converter.
     

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