TH400 34 Element Sprag

Discussion in 'The "Juice Box"' started by 1969RIVI, Feb 16, 2019.

  1. 1969RIVI

    1969RIVI Well-Known Member

    Well my Borg 34 element sprag showed up today!! Another part to add to the pile for spring rebuild.
     

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  2. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    Wow, Made in USA, amazing!
     
  3. 1969RIVI

    1969RIVI Well-Known Member

    Yeh it's a nice looking good quality piece!
     
  4. Bens99gtp

    Bens99gtp Well-Known Member

    you wont have any issues with that part........just make sure when you put the race on that when holding the drum the outer race and sprag facing up, that the outer race free spins in the clockwise direction. it will go on both ways, if backwards you will feel stopping power the instant you go into second gear like you never dreamed was ever possible........I know this from personal mess up................I will never ever make that mistake again. lol
     
    Last edited: Jan 7, 2020
  5. 1969RIVI

    1969RIVI Well-Known Member

    I've read that a few times that it MUST be put in properly or I'm in trouble! I've burned that into my brain for sure lol
     
  6. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    I did that on my first 425 fwd cadillac transmision build.
     
  7. 1969RIVI

    1969RIVI Well-Known Member

    UPDATE: Today I bit the bullet and ordered a custom built 9.5" torque converter from Jim Weise at TSP. So a transgo 1-2 kit and a new flex plate from TA is all that is left to get for this TH400 rebuild.
     
  8. 1969RIVI

    1969RIVI Well-Known Member

    And it arrived!! JW "the wheel" flex plate and Transgo 1-2 kit is enroute and should be here soon.
     

    Attached Files:

  9. 1969RIVI

    1969RIVI Well-Known Member

    JW flex plate arrived today, just waiting for the transgo kit!
     

    Attached Files:

  10. 1969RIVI

    1969RIVI Well-Known Member

    So my transgo kit showed up last week but I've been super busy with work. Now that all the pieces are here it's time to find some time to drop the trans and get to it!
     

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  11. Gary Bohannon

    Gary Bohannon Well-Known Member

    Do these sprags just drop in that sawtooth shaped hole?
     
  12. 1969RIVI

    1969RIVI Well-Known Member

    No it goes on the direct drum on a smooth surface and only goes one direction, locks up if you try to turn it counterclockwise. If you put it on the wrong way and assemble the trans the first time out you'll know you made a big mistakeo_O:eek:
     
  13. Bens99gtp

    Bens99gtp Well-Known Member


    There were 2 type of direct drums used in the 400, 1st is the earlier builds which used a smooth inner race but only a 16 element sprag. 2nd is a roller sprag which has the sawtooth looking inner race. Only the 1st design is upgradable to a 32 element sprag. The 2nd design is better at holding than the 1st.....until you upgrade the sprag. You can also find this smooth drum in the newer 4l80 transmission.

    Oddly enough in the early years of production the low sprag was also a multi element design, it was change out in favor of the roller design b4 the direct drum coming from gm.......per my conversation the other day with a rep. from coan specifically about this low roller.......they feel that roller design in this location is more than adequate for the the needs, and even in their own designed reaction carriers use a roller set up not a multi element unit. He indicated he didnt feel its would be worth the this issue to locate on for the internal component lightening I plan to be doing
     
    1969RIVI likes this.

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