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Technical 700r4 again

Discussion in 'The Hokey Ass Message Board' started by flatmotor40, Apr 15, 2015.

  1. flatmotor40
    Joined: Apr 14, 2010
    Posts: 516

    flatmotor40
    Member
    from georgia

    Finely got the 700 back for the 2nd time since Nov and it seems fine except when you go to reverse it really hard shift into reverse.You had better have foot on brake.He did it without any lockup wiring at all.Having a hard time with this trans gut any help Thanks.It seems to shift into OD but not locking up converter will it lower rpm more.
     
  2. When the converter locks in 4th gear the rpm will drop
     
  3. The lockup will eliminate any torque converter slippage and thus reduce engine RPMs.
    It sounds like you either:
    1. have a pre 1987 trans
    2. or your TV cable is not adjusted properly and has too much pressure at idle speeds causing the harsh shift into reverse (it should also be harsh shifting into drive)
     
  4. flatmotor40
    Joined: Apr 14, 2010
    Posts: 516

    flatmotor40
    Member
    from georgia

    Will keep on adjusting TV cable.Have Lokar cables on the engine since it has a TPI set up
     
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  5. okiedokie
    Joined: Jul 5, 2005
    Posts: 3,687

    okiedokie
    Member
    from Ok

    Hook up a pressure gauge and see what you the pressures are. Your trans guy should have done it if he installed it.
     
  6. flatmotor40
    Joined: Apr 14, 2010
    Posts: 516

    flatmotor40
    Member
    from georgia

    He is not a very good trans guy tired of fooling with him.When it quits raing I will get at it again adjusting tv cable.Thanks
     
  7. I hope you get it figured out, because that trans is real fun when it works correctly. The pressure gauge comment is true. According to Bowtie overdrives, the pressure should rise as soon as the throttle is pushed. Their web site may have some usefull info for you, or give them a call. I'm not familiar with the Lokar cable, I've only ever used the Bowtie set-up.
     
  8. flatmotor40
    Joined: Apr 14, 2010
    Posts: 516

    flatmotor40
    Member
    from georgia

    Thanks.I don't think the trans guy even owns a pressure gauge
     
  9. 48FordFanatic
    Joined: Feb 26, 2011
    Posts: 1,336

    48FordFanatic
    Member
    from Maine

    First thing i would do is to put the wiring and solenoid back in the transmission that it came with . Then wire it with a brake pedal switch and a manual switch for the lockup. That's the way i did mine and it has worked flawlessly for about 20000 miles so far. User a GM TV cable and the correct brackets on your carb and set the TV cable the way GM says ....very simple to set at idle and wide open throttle. When the converter locks up you will only see a drop of about 300 rpm. If the transmission is low on fluid the converter will not lock up , or might not stay locked up.
     
  10. There has been a lot of discussion about weather a stock of after market cable is best.Remember that the cable only has one job to do and that is to move the throttle valve to control TV pressure relative to throttle angle.As long as the cable moves freely and the initial pressure is set correctly at closed throttle then it doesn't matter what cable you use. The key is to pull the cable at the correct rate as the throttle goes through its rotation. If you are using a carburetor that was not designed to be used with the 700r4 then you need to make sure you have some sort of provision to correctly move the throttle valve at the right rate.That's where the geometry comes into play. You need to take into account the length of the throttle arm and the distance that it moves in order to duplicate the correct rate that GM engineered into the system. Usually that involves modifying the linkage at the carburetor or taking the easy way and using an after market setup that has already done the work for you. This usually involves some sort of cam with ramps that bring everything into the correct geometry and alignment. You then can do the fine tuning with your pressure gauge.As far as lock up is concerned if your transmission is 85 and later then you can run without lock-up if you want because GM made changes to the fluid supply vs earlier units but on the pre 85 transmissions running for any length of time without the converter locked in OD will caused premature transmission failure. Always run a high quality transmission cooler as excessive heat is the enemy of the 700R4. There are all sorts of ways to control the TCC from using a simple on off toggle switch controlled by the driver to electronically controlled systems offered on the aftermarket but the factory setup can be easily adapted to most applications and wired as stated above although I prefer a toggle that allows me to override the system if I want. The 700R4 is a great transmission but does require some attention to detail on initial setup in order to realize it's full potential .
     
  11. jaw22w
    Joined: Mar 2, 2013
    Posts: 903

    jaw22w
    Member
    from Indiana

    Do you have the geometry correcting bracket that bolts to the throttle lever on the carb? They are available at Summit, Jegs, etc. You must have this to operate correctly.
    I just had my 700r4 rebuilt. I have a great trans guy. He told me to pull the throttle wide open, pull the TV cable wide open and attach it right there. Worked great on mine and needed no more adjustment.
    I don't know how he wired it inside, but all I had to do was hook it up to a 12V ignition on. It works perfectly.
    As far as rpm drop at lock up, mine shifts into 4th gear and locks up at the same time, so all the rpm drop happens at the same time. I can't tell the 4th gear rpm drop and the lockup rpm drop separately.

    Seems to me the trans guy also said something about burning up 4th gear if the lock up doesn't work. Not sure about that though.
     
  12. flatmotor40
    Joined: Apr 14, 2010
    Posts: 516

    flatmotor40
    Member
    from georgia

    I have a Tuned Port Injection on my engine.It is a later 700r4 so I see that you said they can lock up ay fluid instead of electrical way.I wish the guy would do it like the factory but he says my 383 stroker has too much power for it.The more I talk to him the more I stay messed up.When it quits raining I will drive and adjust cable.The only problem now is going in reverse it is hard.Hope to finish this up Thanks
     

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