Rebuilding my TH400

Discussion in 'The "Juice Box"' started by 1969RIVI, Jun 9, 2019.

  1. Bens99gtp

    Bens99gtp Well-Known Member

    Hole1 look factory, some had a check all in there some didnt,.

    Does hole 1 and the hole 2 connect??? I dont recall having s hole up in where the frictions are, not sure what that would do.

    Where I drill is down by the x, it's under the piston, not above it.

    I dont have a piston in front of me but I think there is 16 spots for spring. I have seen 2 missing b4, but not 4. I always buy new right rate spring.

    In my application it helps release the transbrake faster. But it will also help make a 3-2 down shift faster. It also takes more apply pressure to overcome them so with the extra pressure there is more clamping force in the pack.

    Something like this
    https://www.summitracing.com/parts/...LZsZ1lSMGApzOMbl7DQ2A_l7Kwb8LUQAaAmt3EALw_wcB
     

    Attached Files:

  2. 1969RIVI

    1969RIVI Well-Known Member

    Yes holes 1&2 connect they're the same hole, there's one on each side. My transgo 1-2 kit came with 16 new high rate springs to use. It mentions in the instructions that "when installing these springs it is not necessary to put any special bleed holes in the piston or drum unless the engine RPM is to exceed 7500 RPM" Which mine won't even if I take it to the track it will only ever see 5500 rpm MAX. So I shouldn't have to drill the 1/16" hole but should I still leave the middle drum lip seal and 2nd shaft ring off?? Theres no mention of them in the instructions. Also do I still need to put the 3/8" cup plug in the hole?
     
    Last edited: Jun 15, 2019
  3. Bens99gtp

    Bens99gtp Well-Known Member

    As stated b4 drilling that hole helps in clutch release time and to prevent high rpm self apply. It's totally optional. I do it in all my builds.

    Leave the inner seal on the drum off, you have to have both on the piston, I also leave the second from the top ring off the center support and install the plug cup.......that is the dual feed mod. Make sure you do it. In all honesty if you left the inner seal or the ring off center support and plugged the correct hole it would still be dual fed. But I do both
     
  4. 1969RIVI

    1969RIVI Well-Known Member

    I just want to make sure doing the internal mods and using the Transgo 1-2 kit doesn't conflict with one another? I've read that the Transgo separator plate and springs dual feed also?
     
  5. 1969RIVI

    1969RIVI Well-Known Member

    1/16" hole drilled in bottom of the direct drum, no turning back now! Lol
     

    Attached Files:

    Last edited: Jun 15, 2019
  6. Bens99gtp

    Bens99gtp Well-Known Member

    It is possable that the trans go plate is made to block off the same passage that the plug cup does, I never buy shift kits, i just modify the factory plate
     
  7. 1969RIVI

    1969RIVI Well-Known Member

    The factory plate is gone it's a B&M one there now from P.O. I'm just going to do your mods and use the transgo plate. I read online that doing the mods and using the transgo kit is fine. Did I drill the hole in the correct spot? I read your mod thread and looked at your pic a few times before I drilled it as I only had one shot at it lol. Here's a pic where it came out on the other side of the drum.
     

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    Last edited: Jun 15, 2019
  8. Bens99gtp

    Bens99gtp Well-Known Member

    Looks just fine, just makes sure not burs on the seal side
     
  9. 1969RIVI

    1969RIVI Well-Known Member

    I'm going to deburr both sides with a scotch brite pad.
     
  10. Bens99gtp

    Bens99gtp Well-Known Member

    When you install the sprag it will install both way, so make sure you get it on the correct way
     
  11. 1969RIVI

    1969RIVI Well-Known Member

    So I was able to set up the direct drum with a total clearance of 0.059 by using two 0.0765 steels, one 0.0880 steel and one of my old steel that is 0.0770. Is it ok to mix in an old regular steel with my new kolene steels?? I had to reuse the old wave plate also.
     
    Last edited: Jun 17, 2019
  12. Bens99gtp

    Bens99gtp Well-Known Member

    What is the specs with all the steels being new. There should be no harm in using 1 old steel, the newer steels being kolene with have a different friction ratio

    Some times you might gave to " borrow a steel from the other clutch, sometimes when you only have so many steels, you might have to mix and match and comprise some of the clearances
     
  13. 1969RIVI

    1969RIVI Well-Known Member

    If I swap out the old 0.0770 steel and ad a new kolene 0.0890 steel to the pack with the other steels stated above^^ I end up with a clearance of 0.048. That's using all new kolene steels and the old existing waved steel. I can't borrow a new kolene steel from the forward drum because it's already near the bottom end of the clearance scale at 0.037

    EDIT UPDATE: I air tested the drum with all the new kolene steels and used waved plate installed and took measurements again. It's now reading 0.051 of clearance.
     
    Last edited: Jun 17, 2019
  14. Bens99gtp

    Bens99gtp Well-Known Member

    Perfect,

    They are pretty good on getting those pack clearance correct, sometime ppl get the steels for the forward and direct mixed up and it causes goofy things, sometime you have to swap 1 or 2 to get the clearance a little ballparkishly on both.
     
  15. 1969RIVI

    1969RIVI Well-Known Member

    Yeh it took me a bit of playing around and a bunch of checking to get the numbers to work for the direct drum but I'm glad I didn't have to use an old steel with the new kolene ones. So far everything I've been taking out of this trans has been original except the separator plate and possibly the valves and springs in the valve body.
     
  16. 1969RIVI

    1969RIVI Well-Known Member

    So I've got all the clutch assemblies assembled and all my washers and everything are in place, low reverse band installed. I dropped the whole assembly in........and out a few times. Everything goes in good but for the life of me I can't get the center feed hole to line up to get the center support bolt in?? Any ideas??
     

    Attached Files:

  17. Bens99gtp

    Bens99gtp Well-Known Member

    Are you assembling this on its side or vertically. Are you sure the planetary assemblies are fully together.

    Sometime when dropping through the center support slides up.

    Did yours have the fretting ring below the center support? If so did you get the rings in the wrong order.....they are different thickness. Ig your has the fretting ring, the center support will be approx. 330 thick on the lugs and the ring is about .040.
     
    Last edited: Jun 20, 2019
  18. 1969RIVI

    1969RIVI Well-Known Member

    I have it standing vertically in a bucket lol. I have pulled it out of Saud bucket and laid it on my work bench to try and wrangle it in place sbit but no luck. As for the fretting ring I'm not sure what that is?? I've put everything back in the way it came out.
     
  19. Bens99gtp

    Bens99gtp Well-Known Member

    Not all 400s have fretting ring. 68 and back dont have it, some 69s do, 70 up do.

    It's the very thin snap ring that goes under the center support that it sits on
     
  20. 1969RIVI

    1969RIVI Well-Known Member

    Mine doesn't have it it's a 68 th400. I only have two snap rings for the case.
     

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