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Th350 tail housing thread repair question.

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by BadDog, Dec 31, 2003.

  1. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    After the last wheeling trip the truggy was leaking fluid at the adapter between the trans and the range box. You could see that it was no longer tight there. I finally got it off and it looks like I have stripped all 4 holes. Should have made time to build that skid. /forums/images/graemlins/rolleyes.gif

    Anyway, I rather like this trans and the Th400 is not yet ready to go in. Anyone ever fix those threads (heli-coil, thread-cert, etc.)? Looks like there may not be enough material for it to hold up after drilling out for the thread inserts... /forums/images/graemlins/confused.gif
     
  2. big83chevy4x4

    big83chevy4x4 3/4 ton status

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    yea i have fixed a 700r4 witch is almost identicle. it held up fine.
     
  3. R72K5

    R72K5 Banned

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    best way is to aluminum weld fill the holes and drill and thread new holes, welding shops can do that for you, but its 20 or 40 a piece to have it done, i had this done for trans mnount holes in a th350 case for the trans am when bolt hole broke off on me removing the bolts they were seized horribly



    good lukc
     
  4. 4X4HIGH

    4X4HIGH 1 ton status Premium Member GMOTM Winner

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    There is plenty of room to heli-coil the threads. I have repaired them in the past this way.
     
  5. dyeager535

    dyeager535 1 ton status Premium Member

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    I was thinking the thread-serts were way better than heli-coils because of their design, but last time I needed one (3/8-16) and bought it, I realized the tapped hole needed to be 9/16", which is a huge difference, and in my case, would probably have made the surrounding metal too thin.

    I think the smaller ones aren't so different in original and tapped size, which is what made me a big fan of them in the first place.
     
  6. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Thanks guys, looks like heli-coil it is.

    I just checked and 3/8-16 requires only a 25/64 drill to tap. I thought I remembered it being considerably bigger, expecting about 7/16 to repair a 3/8. /forums/images/graemlins/crazy.gif Of course, last time I used one of these was back around 1990 or so. Must be that "old timers" disease setting in again. Please pass the Geritol...
     

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