Rebuilding my TH400

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

  1. Bens99gtp

    Bens99gtp Well-Known Member

    Yep just standard, but by the time they were using 2 pring plugs for other emission stuff the switch pitch wasnt being produced
     
  2. 1969RIVI

    1969RIVI Well-Known Member

    On a side note Transtec states that all their rebuild kits come with a lip wizard tool I emailed Transtec directly about my rebuild kit and that it didn't have one. They said not a problem didn't ask where I bought it from or anything they just said what's your address we'll get some out to you right away. Here we are a week later and look what shows up. Two thumbs up for Transtec being a solid company and helping out their customers regardless if they bought direct or second/third party.
     

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  3. scubasteve455

    scubasteve455 Well-Known Member

    Mine did not have the tool either.
     
  4. 1969RIVI

    1969RIVI Well-Known Member

    Ben can you post the drum/clutch pack clearances again for me please, I can't remember where I read them? Also is it a good idea to remove the wave plate from the forward drum and just use a flat steel? Is dual feeding the direct drum good for a street car trans or race only? I've attached some pics of the clutches and bands I've pulled out, there's some hot spots on some of the steels.
     

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  5. 1969RIVI

    1969RIVI Well-Known Member

    Some more pics of the drums
     

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  6. 1969RIVI

    1969RIVI Well-Known Member

    Before/after case clean up and paint I didn't take any pics of it coated in 50 years of oil and grime as I'm sure we all know what that looks like lol
     

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  7. Bens99gtp

    Bens99gtp Well-Known Member

    I dual feed all 400 street or strip, it's just better holding in the clutch.

    nothing in your clutches looks terrible from what I can see.

    Removing the wave plate out of the forward drum, or any drum, will mean you need to play a little more to get clearances, everything will apply faster and firmer. So by removing it it could go into gear harder than b4, same as reverse for the direct. Some converter absorbs this better than other......so that's a choice you will need to make. Also dual feeding will act like a cushion somewhat in reverse. Some ppl are more tolerant to a former apply going into 1st and reverse than others, I try to feel this out b4 I build for them.



    I try to set the forward clutch between .035-.060

    The direct at .050-.070

    The intermediate at .050-.080

    You can get away with less in the forward because that clutch does overrun expect in reverse. The other ones I run a touch more in so they dont drag when not engaged.

    General rule of .010-.012 per friction plate is fairly true for most transmission. Larger diameter clutches sometimes like a touch more

    Here is the link to the write up I did earlier if you cant find it

    http://www.v8buick.com/index.php?th...w-easy-internal-upgrades.342929/#post-2903658
     
    Last edited: Jun 14, 2019
  8. 1969RIVI

    1969RIVI Well-Known Member

    Thanks Ben! Upon inspecting the trans I thought it looked pretty healthy other than it leaked pretty bad out the front and a bit on the tail seal and it shuttered when backing up. I'm going to replace everything so I know that it's all fresh. I don't want the trans to "jolt" abruptly into first or reverse so I should probably leave the wave steels in then. My kit only came with one wave steel I'll probably have to reuse one of the old ones.
     
  9. 1969RIVI

    1969RIVI Well-Known Member

    Is trans gel necessary to put it back together or can I just use trans fluid to lubricate and Vaseline to help stick the washers while assembling?
     
    Last edited: Jun 14, 2019
  10. Bens99gtp

    Bens99gtp Well-Known Member

    That a what I do
     
  11. Bens99gtp

    Bens99gtp Well-Known Member

    Sometimes those hot spots get formed from the wave plate cause it doesn't apply evenly across...........just sand then smooth.

    Take time on all the thick reaction plates......thick top plate on each clutch assembly, and make sure the bottom surface is flat, might need a file or sander to do this...........not just a 2" surface prep disc.
     
  12. 1969RIVI

    1969RIVI Well-Known Member

    "Take time on all the thick reaction plates......thick top plate on each clutch assembly, and make sure the bottom surface is flat, might need a file or sander to do this...........not just a 2" surface prep disc."

    Ben can you elaborate a bit more on this I'm not quite following what you mean? I have all new steels and frictions going into the trans.
     
  13. Bens99gtp

    Bens99gtp Well-Known Member

    The very top thick plate, the part just below the snap ring. Make sure the surface that the last clutch plate hits is as flat as you can get it for all 3 clutches.


    From your pictures. The red arrow is the reaction plat for the direct clutch, the forward clutch would be the plate that extends into the direct clutch when assembled, the reaction plate for the intermediate looks very similar to the direct but thicker. You can order these in different thickness if needed to help taylor pack clearance.
     

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  14. 1969RIVI

    1969RIVI Well-Known Member

    Oh ok got ya now. Right now I'm working on the forward drum I have one wave plate that is 0.060 and 4 steels that are 0.0765 along with the frictions and I have my feeler gauge put in between a friction and a steel. At .030 I can wiggle it easy, at 0.033 I can move it but it's really snug. Is 0.030 good for the forward drum? Or should I get it a bit bigger?
     

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    Bens99gtp likes this.
  15. Bens99gtp

    Bens99gtp Well-Known Member

    I dont use feeler gauges, the angle makes it tough and I dont want to bend all my sets up. I have .020 washers that are ment as rocker stand adjustment for a SBC. I use them as go/no go, and just stack them up on the last clutch b4 placing the reaction plate on. I start with 3 stacks at .040. If I can seat the snap ring and turn and wiggle the plates with a pick I have clearance.....I start adding .020 to each pile to find what I'm am between.

    With a wave plate. 4 steels, and 5 fictions your getting very close to minimum specs I'd be happy with, have you applied the clutch with air yet, if not do that and recheck......sometime the action of moving the piston up and down a few time causes it to settle back some and gain clearance
     
  16. 1969RIVI

    1969RIVI Well-Known Member

    Yes I've applied air to it and everything is moving. I now have the 0.060 wave plate, three 0.0765 steels and one 0.0880 steel in the drum. I found a sawzall blade that is .038 thick cut it into 4 pieces and (debuured it so it won't damage anything) put them into the drum. The snap ring goes on snugly but I can't turn the plates with a pick like you said. I have another blade that I can cut into shims that are 0.0345 I'll try them and see if I can get them to spin. Is that what I'm looking for snug pressure but able to just move the clutch plates with a bit of force?
     
  17. Bens99gtp

    Bens99gtp Well-Known Member

    If the snag ring locks in but cant turn them I would say your right about. 037. Cause if your shim is too thick the snap wont lock in.

    Your on the tight end but should be good, if you had a flat steel instead of a wave you would be closer to .050. I think you will be just fine with that one
     
  18. 1969RIVI

    1969RIVI Well-Known Member

    I put the 0.0345 shims in and it's still really snug but I could move the top friction a 1/16"-1/8" back and forth with a pick. Should I leave it and move on? I don't want the harsh shift in 1st or reverse so I think I should keep the wave plate in.

    EDIT: I put 0.0395 shims in and I had to really fight and press the snap ring down to click in and there's no movement of the clutches with the pick and the piston barely moves when applying air. So I think you're right Ben saying its probably around 0.037
     
    Last edited: Jun 14, 2019
  19. Bens99gtp

    Bens99gtp Well-Known Member

    I think your ok on clearance for that pack. The forward only overruns in reverse. So it can drag a little but and not hurt. The other 2 you will want more clearance.

    If your having to fight the snap ring on it's too tight. But the shims gets a more even measurement, where a feeler gauge you can get the pack to lift on the side opposite the feeler and get a slightly false reading.

    Dont forget to put your hub and washer under it b4 cslling that pack complete. I put the hub in first then load the pack in.......it can be a turd to fight the hub all 5 frictions.

    When you do the direct b4 you call it done, pull the reaction plat back off the forward and run it through the frictions to line then up, will make it easier to get the last drum in place
     
  20. 1969RIVI

    1969RIVI Well-Known Member

    Ok excellent! I moved on the the direct drum and started to take it apart then it happened.............my clamps gave way when I pulled the retainer ring off and BANG!! springs everywhere!!!!:mad::mad::( So how many springs are supposed to be in the direct drum? I found 12 and judging by the witness marks on the spring retaining cap it looks like there should only be 12. On a positive note my direct drum looks like it already has two 1/16" drain holes from factory on the bottom that you mentioned in your dual feed mod Ben. Or are these feed holes to the clutch plates?
     

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    Last edited: Jun 14, 2019

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