Anyone here ever use th250 trans on their 455?

Discussion in 'V-8 Buick Powered Regals' started by usetaboost, Aug 22, 2015.

  1. usetaboost

    usetaboost Well-Known Member

    I got the holes reamed out on the flywheel. Tried pulling the converter forward and its probably about 3/8 of an inch from the flywheel. Can't get it to move any further. Is this normal for late model transmissions and the 455? Or is something screwed up?
     
  2. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    If you pull the converter out too far, you will hurt the front pump drive. 3/16" is the measurement from flex plate to converter. Use a washer or two to take up the excess. You meant THM350, not 250, right?
     
  3. usetaboost

    usetaboost Well-Known Member

    Nope its a th250 lol I checked. I just need it to move the car around and get to the exhaust shop. Going to pick up a real trans for it at the end of next month.
     
  4. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    The converter hub drives the transmission front pump. The hub has 2 slots in it that mate up with the pump drive tangs. Use some washers.
     
  5. usetaboost

    usetaboost Well-Known Member

    OK. I was just unsure. This is the first time I've ever run into an issue like this, even with aftermarket converters. I'm guessing that hub on the converter must be too big to set in the back of the crank.
     
  6. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    You don't want it to bottom out in the crank, you'll push the crank and wipe out the thrust bearing.
     
  7. usetaboost

    usetaboost Well-Known Member

    Right. I might loosen the trans just a bit just to make sure nothing is binding or crooked and go ahead with some spacers and longer bolts. It isn't like I'm gonna race it. Probably gonna go in the scrap pile after I get my new trans anyway lol. Thanks for the input. Hope to be able to take this bad mofo around the block today.
     
  8. TheSilverBuick

    TheSilverBuick In the Middle of No Where

    It'll probably put itself in the scrap pile. Definitely make sure the torque converter isn't hitting the crank, and drive gently.
     
  9. usetaboost

    usetaboost Well-Known Member

    Got it popped in. Just loosened the trans bolts a bit is all it took. Must have been in a slight bind. I made the holes for the flex plate a little big. It will have to do for now. Does anyone offer a zero balance flexplate with the holes already drilled for other converters besides the th400?
     
  10. usetaboost

    usetaboost Well-Known Member

    Oh he's, its destined for the heap lol
     

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