Help! Transmission trouble...

Discussion in 'GM Powertrain' started by Eric.Wayne, Apr 18, 2009.

  1. Eric.Wayne

    Eric.Wayne New Member

    Just bought a '92 c1500 5.7 L with 700r4 tranny, the truck sat for 10 months before i bought it and it doesn't want to shift out of 1st until it gets good and warm after about 20 minutes or so. I am going to swap tranny's next week if I can't figure something out. Thanks
  2. Dr_Zero

    Dr_Zero Epic Member 5+ Years 500 Posts

    Have you tried a flush and filter change? No telling how old the fluid is and it could be kinda thick and doesnt thin out enough till it gets warm and flows better and thus the delay in shift times.
  3. Eric.Wayne

    Eric.Wayne New Member

    Not sure if we "flushed" it, we did change it and put a new filter/gasket in. Someone told me that the o-rings have probably hardened and I could use a "conditioner" but eventually it would eat away the o-rings. if I can't find a permanent solution then I am just gonna swap for a rebuilt one I guess.
  4. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    Here's a little trick that just might work if the TV valve is hanging up. You can do this very easily but it takes both hands or a helper. Removing the air cleaner may make it easier if you can't get your hands in close to the TV cable.

    First thing you want to do is release the TV cable from the throttle body. Start the truck and make sure it's in park with the E brake on.
    Next use your left hand or have someone raise the engine RPM to about 2000 RPM. Now with the engine screaming at 2K pull the TV cable out all the way and then back in. In and out in and out as fast as your wrist can repeat this action. Do it at least 25-30 times in a row while the engine is running @ 2000RPMs.

    This little trick works most of the time on 700R4 transmissions if the TV valve is stick in the valve body.

    Try this when the engine is cold and it's acting up. Let us know if this works!
  5. Eric.Wayne

    Eric.Wayne New Member

    I will give it a shot, i will let u know.
  6. Eric.Wayne

    Eric.Wayne New Member

    I am gonna try this tomorrow I just have one question, if the truck is in park the whole time, how exactly does this help? I will let u know.
  7. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    Increasing the engine RPM increases the line pressure which in turn helps flush the crap trapped in the TV valve. It will work at an idle too but I've found the high RPMs works best.
  8. Eric.Wayne

    Eric.Wayne New Member

    I really appreciate youur help, it looks like we're just gonna have to replace it, we have a wicked vibration too and we have already checked the u-joints and balanced the driveshaft but it is still there. It must be in the transmission somewhere. The speed sensor gear and sensor itself was bad anyways so it had to be done eventually, I would like to know how fast I'm going and use cruise control from time to time. Thanks for your help Jimmiee!
  9. retired

    retired Rockstar 100 Posts

    You will probably need a new flex plate if you have a vibration.
  10. Jimmiee

    Jimmiee Epic Member 5+ Years 1000 Posts

    Make sure you get a second opinion before you buy a transmission. Good Luck!

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