TH350 or converter??

Discussion in 'The "Juice Box"' started by deluxe68, Apr 1, 2014.

  1. deluxe68

    deluxe68 Well-Known Member

    I have two things going on here that might not be normal.
    1. The car shifts very, very fast I mean I'm in third gear at around 20 mph.Second gear at about 10 feet into movement.
    2. You can barely feel the car shifting, you can hear it a little but notreally feeling it. If you shift from the column you can feel it though.
    Is this a trans or converter issue? I just installed anew vacuum modular and the same thing is going on.
    The TH350 and the TA 2500 stall converter both have about 600 miles on them.
    If this is not normal what should I be checking out first?

    BRUCE ROE Well-Known Member

    Its not a converter issue. Might be the governor, or that and some other issues. I had a TH400
    that I modified the governor on, with a spring & weight kit. Got it to shift about right, also using an
    adjustable vacuum modulator. Bruce Roe
  3. deluxe68

    deluxe68 Well-Known Member

    Thanks for the insight, I'm going to take it to the person who did the rebuild.
  4. rmstg2

    rmstg2 Gold Level Contributor

    Did you check the kick down cable? Even with governor problems if the cable is hooked up it would still stay in second until at least 60 mph. Good Luck

    Bob H.
  5. deluxe68

    deluxe68 Well-Known Member

    Took the car to the tranny shop and they said bring it back in 2 weeks and they will look at it.
    It was a really nice day here in PA so I looked at the kick down cable today.
    Not only do I think that there is a problem with how fast the tranny shifts, it seems to me that I do not have the passing gear either.
    With the pedal to the floor I pulled the kickdown cable as far as it would go and then tightend it up. the gas pedal was already set so there is no extra throttle linkage travel.
    So it seems that the pedal goes down about 3/4 of the way and then when you floor it you get that extra pull in the kickdown cable.
    If the car is shifting into the passing gear I really can't feel it. You are supposed to feel it correct? Does anybody no what is going on here?

  6. rmstg2

    rmstg2 Gold Level Contributor

    With the power you have with a healthy 430 you would definitely know if it went into passing gear.

    Bob H.
  7. snakegrayc

    snakegrayc New Member

    With It Sounds Like A Shift Kit Was Installed. It's In 3Rd Before You Get Across A Intetsection right? hold It In First Manully And bAng Second Bet It Barks Em And Don't Know Why This Phone Caps Every Word Good LuckH
  8. Tinz

    Tinz Active Member

    Did you install an adjustable vacuum modulator?
  9. deluxe68

    deluxe68 Well-Known Member

    YES I installed a new vacuum modulator. I turned it 1/2 turn at a time (about two turns total) it helped a little but not really much so I turned it back around half way.

    "snakegrayc" is right on with everything stated, does the shift kit have something to do with this?
    It is alot of fun manually shifting this car.

    Shop did tell me to drop it off and they will look at it, I personally think they forgot to rebuild "it" or some part of it. vacuum modulator was old. What else is?
  10. snakegrayc

    snakegrayc New Member

    It Is Completly Normal Thats What A Shift Kit Does Makes Shifts Faster And More Positive . Sounds Like Your Trans Builder Did A Fine Job You Can't Adjust It Out Unless You Change Goverernor Weights . Or Reprogram Hydraulic Circuits .The Governor Mod Is Easy Just GriNd Weight Off The Governor Weights A Little At A Time A Spare Is Best To Practice With Or B&M Sells A Kit What Freaks Me Out Is Nobody Here Has A Shift Kit? Every One I've Done Shifts Like Yours But The Fast Shifts Will Improve Milage A Little Let Me Know If You Want The Grinding Dimension For The weights It Sounds Like The Kickdown Cable Is Out Of Adjustment It Should Drop Into Second To Pass The Shift Kit Shouldn't Change That Call The Shop And See If They Did Anything To That Circut

    BRUCE ROE Well-Known Member

    My own experience, you might have to turn that modulator screw half a dozen turns to get where you want to be. Bruce Roe
  12. deluxe68

    deluxe68 Well-Known Member

    I agree, I would have done that but I was not sure if the screw does in fact bottom out.
  13. Geoemojr

    Geoemojr Guest

    My th350 is running with kickdown cable not hooked up cause dang cable won't stop leaking fluid out of it when converter sits a few days and drains back into it. I haven't gotten around to fixing it yet. LOL. Anyways I have a TCI stall and a B & M shift kit, special vacuum modulater in it. What you are describing is my transmission without cable hooked up. Sounds the same. Is it connected at pedal right. Then maybe it isn't connected in tranny?
  14. deluxe68

    deluxe68 Well-Known Member

    Thanks for all the input everyone,
    shop test drove the car and said it shifts "great'. We adjusted the modulator 4 more turns and it shifts into third around 30 mph now. I did have the cable installed correctly, they did say it's a shame that either the cable is not hooked up inside or there could be a valve body issue. One way or another it is going to get fixed soon.
  15. deluxe68

    deluxe68 Well-Known Member

    The governor is what ended up being the problem as far as the very fast up shifting.
    I am ready to fine tune the shift points if this SHIFT Technology Products kit will work.(what the trans shop purchased)
    According to the chart they set it up for a police 5.7 V8 (C&F weight and orange and red spring) Looks to me about 1 step up from the middle of the chart.
    I have no idea at what the norm is, but right now the car shifts from 1 to 2 at 25 mph and then at around 45 it will shift to third (normal take off)
    Is what I have good, a good starting point and or should I try to improve on it?


    BRUCE ROE Well-Known Member

    The trans doesn't know your axle ratio & speed, it goes by rpm in & out. With a 2.41 axle
    & big tires, flat out I shift to second at 60 mph, third at 100 mph. Bruce Roe
  17. deluxe68

    deluxe68 Well-Known Member

    Since I'll be ordering a TSP converter soon, I just have not made my mind up yet about changing to a 200 r4 or keeping the TH350 that I already have. I do like the idea of having OD but,
    I am leaning towards keeping what I have and just doing an upgrade to it while it's already going to be out of the car.

    So I have been looking for performance rebuild kits for the TH350 and found one from Monster.
    It's the SS Mega Monster rebuild kit, has anyone used this kit before??? Happy with it?
    Any other good suppliers out there besides B&M, TCI etc. that would be good?

  18. deluxe68

    deluxe68 Well-Known Member

    Winter project is coming up fast, has anybody used the Monster kit?

  19. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Minimum throttle shift points should be lower than what you have. It should shift 1-2 at about 10 MPH and 2-3 25-30 MPH. The more you step on it, the higher the shift points should go. You need to check the wide open throttle shift points also.
  20. deluxe68

    deluxe68 Well-Known Member

    After I started adjusting the modulator, the shifts were about 15 and 30 so I was happy with that.
    Under normal acceleration the transmission shifts fine.

    But have developed a new problem which is leading me to believe I need a swap or rebuild done.

    Here is the symptom: from a dead stop I roll out just a little to not spin the tires then floor it.
    Car takes off but hangs in first gear long enough for it not to pull anymore so I let off the pedal at this point.
    I tried it again a couple days ago and the same thing happened.

    Now if I do the same thing at 1/2 or 3/4 throttle the car shifts fine through the gears (say about 3-4000 rpm shifts)
    If I manually shift from a stop I can run through the gears at 5-5300 rpm BUT, a short time after I hit third gear
    the car just lays down in the middle of what feels like to me is that it was still pulling.

    So I know this probably sounds really strange but this is what is going on and I don't want to get the TSP stage 1 converter
    until I figure out what's going on and make a decision on what direction to go.


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