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700R4 Lock up in Stude.

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  • 700R4 Lock up in Stude.

    I'm going to put a 700R4 chevy trany in my 56 pickup. I stopped and talked to the local transmisson shop about converting the locking coverter to be used in this pickup. He said that he don't use the elecrical lock out he puts a spring in the valveplate that will shift to lockup a about 45 mph so no need to run wirers to stop lite switch. my question is are there differnt ways of rigging this trany to work

  • #2

    Just google 700R4 lockup switch and you will find a ton of ways to do it.



    • #3
      While I'm partial to the 200-4R, the same holds true.
      I'd go with the electrical switch.
      The reason I like the that I had a 700-4R (I know it's bad points) in a 67 Chevy II, I used to have.

      I had the electrical lockup setup in that...after trying other arangements, and it worked out best, for me.

      One thing...I seriously doubt you want the lockup in at 45mph. Not unless you live in one of the plains states, and all of your driving in in the wide open..!

      My setup was to have a manual switch...that way the trans. wasn't hunting or consistantly going in and out of OD at 40/45mph. That would drive me nuts!

      Good luck.



      • #4
        Buy the BowTie overdrive kit.

        It will give you lock up in 4th gear only and you won't get the "chuggle" associated with lock up in the lower gears. With this kit the 700 will unlock with light to medium acceleration in 4th and re-lock at steady cruise. It's virtually invisible with the exception of a noticeable drop in rpm and quieter cruising when it's locked. A feeling that is quite comfortable because it's the same as most daily drivers.

        The installation is downright simple. Some remove and replace, a couple of splices and that's it. The stoplight circuit is a little more involved but as I said I found that it really wasn't a critical addition.

        In the kit, there's a pressure switch and a self grounding lock up solenoid, wiring etc. It also includes the stoplight wiring and relay although I ran mine without that hooked up. The stoplight relay is to keep the car from stalling should you make an emergency stop so quickly that the trans doesn't downshift and come out of 4th gear leaving the converter locked.

        You can also wire a toggle switch in addition to automatic lock up with this kit but I never found the need to do so.

        May I also suggest buying TCI's constant pressure valve body. I've had multiple issues with my 700 installation all stemming from TV cable adjustment or should I say improper adjustment. So much so that I now have a 200 in my Avanti ( long story ).

        The valve body keeps enough pressure to the clutches no matter where your TV cable adustment is. You can then "play" with the TV cable to get part throttle shift points from soft and quick to longer and harder and stops in between. With the 700 ( especially if it has upgrades like a Corvette Servo and shift kit) high line pressure, which will keep the trans alive, can also result in a very hard and extended 1-2 shift. The low 1st gear on this trans just exacerbates the uncomforatble 1-2 shift. Adjusting the TV cable to bring line pressure down and make the shift from 1st to 2nd more comfortable may result in improper downshifting and lower line pressure on cruise. The TCI Valve body eliminates the chance of burning up the 3-4 clutches due to low line pressure.

        Under no circumstances should you run without lock up in the 700.


        On its way to a 15.097 Spring 2006.


        • #5
          My 2 cents , most kits cost a arm and a leg for what you can buy cheap. On my m5 project I am running a 700r4 with shift kit and vette lock up converter. All that was required was following. 1. buy the plug if you don't have it already to go on transmission.2. Inside the trans is a 4th gear pressure switch. All that happens is current leaves fuse box, goes thru brake switch ( thru cruise control circuit, on to the plug, goes in trans to the 4th gear pressure switch (need 2 pole switch on 4th gear), out other side of switch and on to solenoid for converter, than out other side of solenoid back to entry plug and outside goes to ground (i grounded on pan bolt. Reason for me going thru brake switch was to kick out lock up when braking, may not be needed due to only locks up in 4th gear. Most kits have a lot of parts for 200r4 that you don't need. My trans does great, and with 3:73 gearing, runs 1500 rpms at 55 mph when in overdrive and converter is locked. lockup also reduces the transmission temperature which will prolong the life of the tranny. I put a dash switch on my truck for fear of tranny kicking in and out of lockup at a given speed, but have not had the problem or need for the switch.I know this isn't all the info you need, but I didn't take pictures when I had pan off .

          Randy Wilkin
          1946 M5 Streetrod
          Hillsboro,Ohio 45133
          Randy Wilkin
          1946 M5 Streetrod
          Hillsboro,Ohio 45133


          • #6
            I took all of your advice, Called TCI and think I will go with a valve body and there vacuum controlled lock up switch. TCI explained that with there vale body it would keep the right amount of presser on 3rd & 4th gear as to not burn up the clutchs if you did't get the throtle cable adjusted rigth. thanks Ken.


            • #7
              Buy a B&M lockup kit ($176 from Summit)
              This kit has a speed sensor & you can adjust the lock point quite precisely, while under way.
              Run the power through the B&M controller into the trans and over to one wire of the TC lockup solenoid. Then, ground the other solenoid wire to a pressure switch installed in the 4th-gear pressure point. It is not necessary to get a 2-pole pressure switch if you use the switch as a switched-ground only.

              This lets you set it 1-2-3-4-4locked, to suit conditions.
              I don't suggest lockup during very low speed or low RPM conditions, especially if chugging occurs. I wouldn't lock it during gear changes either.

              Optionally, you can run a micro-switch in the throttle linkage to let you unlock at higher openings.

              Best of all, throw away that dreadful 700R4 & put in a 200R4 with a shift kit & upgraded 2nd gear servo. The 200 is ever so much better than a 700. I just put this exact setup in my 66 El Camino, and just to let you know how strongly I feel about this, I went out & bought & rebuilt a 200R4 rather than use the freshly rebuilt 700R4 boat anchor under the bench.