Rebuilding my TH400

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

  1. 1969RIVI

    1969RIVI Well-Known Member

    Here's a short video of my new JW "the wheel" flex plate and 9.5" torque converter from Jim Weise at TSP. No more wobbling!!!:p:D

     
  2. Bens99gtp

    Bens99gtp Well-Known Member

    Under normally driving, like driven through a downtown district, normally the 1-2 shift should happen near 15mph, and the 2-3 about 25-30.

    If you didnt change anything with the governor, it should only be a vacuum modulator adjustment to get shift timing to ve back to where it was
     
  3. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    The modulator adjustment is limited. Maybe 2-5 MPH. Turn the adjuster in clockwise for later shifts, back it out for earlier shifts. Minimum shift points in my car are 12-15 MPH (1-2) and 28 MPH (2-3). The governor has some influence on this as well. The converter will soak up a little of the shift feel. I run my adjustment in 2 or 3 turns. I feel the shifts more.
     
  4. 1969RIVI

    1969RIVI Well-Known Member

    I never changed the governer at al. I paid a bit more attention to the shifts at slow intown driving and it seems to be 1-2 shift around the 15mph (1500rpm) mark and the 2-3 shift between 25-30mph (1500-2000rpm). So I don't think I have to really adjust anything then. The "thud" I feel in the 1-2 shift is that the crisp firm shift everyone talks about? I don't feel it on the 2-3 shift? I drilled both holes A&B on the separator plate at 0.125" (1/8") so maybe it's a firm 1-2 and a softer 2-3. If I went up to say 0.140 (9/64") on the Hole B I would probably have that firm thud right?
     
  5. Bens99gtp

    Bens99gtp Well-Known Member

    May or may not, your have now twice the piston area your filling for 3rd, and there is no way to tell how the converter absorbs some, how is it when you run it up to 5000ish in both gears, in lighter driving condition line pressure is lower too. ........so b4 planning on adjusting anything get the full picture.

    If the 2-3 shift at rpms is quick and not a slide shift, but doesnt shift so hard to bark the tires I guess you need to figure out if or how much more you want from it.


    The thud????? It could be just a nice firm shift, could be play in rear, hard to give an answer by an adjective like that, when we cant be there to feel the same thing your feeling.

    Did you remove the large cushion spring in the low/reverse servo cover.

    Did you remove the spring in the valve body in the 2-3 accumulator
     
    Last edited: Jun 23, 2019
  6. 1969RIVI

    1969RIVI Well-Known Member

    I haven't taken it it up to 5000 yet I had the wife and kids in the car and there were tons of cops out today:rolleyes:. I live in a beach town so the weekends we get alot of party animal drunks so hence the influctuation of police presence lol. I will take it out on the hwy just outside of town one night this week and get some results. Now when you say take it up to 5000 in both gears I assume you mean manual shifting correct? Probably a dumb question but I'll ask anyways to make sure.:rolleyes:
     
  7. Bens99gtp

    Bens99gtp Well-Known Member

    The feel really should change either way, where did it shift at b4 when left in drive. I just picked 5000 to be high enough in the rpms to get a good load test.......some ppl dont twist motors ss high as others
     
  8. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    You should be able to get a good idea how hard it shifts higher up in RPM. The only way I can do that is if I bolt on the drag radials. I can't get anywhere near more than half throttle without the car going sideways.:D
     
  9. 1969RIVI

    1969RIVI Well-Known Member

    I honestly don't remember exactly but the 1-2 shift was probably in the same range just softer so maybe I never noticed it as much as I do know. I'm pretty sure the 2-3 shift was later but harder. The old B&M kit that was in there had 3 check balls a green inboard spring and pink outboard spring in the 2nd accumulator valve. I installed an orange inboard and red outboard.
     
  10. Bens99gtp

    Bens99gtp Well-Known Member

    See I cant help you with that setup, when I do mine I eliminate the spring completely in the valve body, 2-3, accumulator and the very large spring inside the low reverse servo.....which is the 1-2 accumulator
     
  11. 1969RIVI

    1969RIVI Well-Known Member

    Your engine is also a sweet JW build Larry :p. You're comparing your apple to my dried up rotten grape lol:D:p
     
  12. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    I understand that:D:D I kind of miss the days when I could easily check my WOT shift points. I could ease it from a dead stop and slowly mat it staying in first gear to the shift point, then take it out on the highway and mat it at 60 to check the 2-3. Now I need to worry about traction all the time on regular street tires. Also, in NY, speed limits have decreased and there are even more cops (State Troopers) all over the place. Hard to test.:)
     
  13. Bens99gtp

    Bens99gtp Well-Known Member

    When I still a full auto shifting Tran in my car running low 11s, the way I has in my write. My trans would shift firm enough the car would drift a little on the track with slicks on. But when driving in the pits, it felt almost like nothing at all.........I miss being able to leave it in d coming back.

    That trans went to Ny to a board member
     
  14. 1969RIVI

    1969RIVI Well-Known Member

    The spring in the 2-3 accumulator piston is out and gone it was removed by whoever put the B&M kit in. I didn't remove the big spring inside the rear servo assembly.
     
  15. 1969RIVI

    1969RIVI Well-Known Member

    That trans was probably pretty stout Ben! I think I need to play with mine a bit and do some high rpm WOT manual shifts to check where I'm shifting at like you guys said. I will see if I can get my wife to video my test runs to show how the car reacts and document my speed and rpm's while I'm shifting and post them here for you guys to get a better idea of what I got. I'm new to all this "tuning" stuff but man its fun:D
     
  16. 1969RIVI

    1969RIVI Well-Known Member

    So you've crossed the line of "too much power" for the streets Larry ;) that's why I want to have a fun powerful car but mostly streetable. I will see the track MAYBE once a season as its 3 hrs away. Most of my fun is on back roads and dark highways:cool:
     
  17. Bens99gtp

    Bens99gtp Well-Known Member

    It's nice to see someone willing to tackle their unknowns, get their hands dirty and try something new and accept they may or may not get it right the first time. I commend you on taking a chance at it.

    Now you know more what it takes to do one, and will know a little more of the when's and why's to adjust or if something goes wrong later on
     
  18. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD"

    No, the car is still a blast to drive and very street able, I just need to exercise due caution knowing it's capabilities.:)
     
  19. 1969RIVI

    1969RIVI Well-Known Member

    True enough! Taking caution with a very powerful toy is smart especially on the streets. I hope to have a similar build to your engine but maybe a bit bigger cam, I like me a nice lumpy cam:D
     
  20. 1969RIVI

    1969RIVI Well-Known Member

    Thank you for the kind words Ben very much appreciated! I love diving head first into things and learning what makes things tic. I appreciate your help and all the other members on here that spend countless hrs sharing tips, tricks and knowledge. This site is truly amazing and it helps so many enjoy their cars and the fruits of their labour!
     

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