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GM 700R4 Manual Torque Converter Lockout

4K views 1 reply 2 participants last post by  BogiesAnnex1 
#1 ·
So there's a few threads on how the wiring is on these or how to put a manual switch, but I couldn't find exactly what I was looking for. Everyone has 3 wire plugs and a vacuume sensor for the Lockout to engage/disengage blah blah blah.
I'm running an 83 GMC originally k1500 with 6.2 and a 700r4 that is not the original. The truck only has 2 wires to the harness, one from the brake switch and another from what I belive is a throttle position sensor. My Lockout was always funky it seemed to me locking/unlocking at odd times and I put another trans in (broken internals) and it does the same.
Being a gutless diesel with 4.10 gears that often tows a truck I wanted to control this a little better.
Manual Lockup on the highway for milage, manualy unlock while towing for power, and around town driving.
I found some and also drew up some diagrams if I were to put a solenoid on the brakes but the brakes or throttle sensor could override it (more concerned of the throttle sensor)
I've read putting power to the hot wire will engage it in 4th and a switch on the ground wire for 3rd but didn't belive/understand how that would work. See other diagram.
My questions are,
If I apply power what does the Lockout do in any gear?
And
If I cut ground what does it do?
 

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#2 ·
You really only need to control the 12 volt power to the connector on the driver side of the transmission.


You can make it complicated as most kits do or simple.


Kits typically involve a vacuum switch on the engine to allow or not engagement based on throttle position's impact on vacuum, high cruise vacuum allows, low gettin' on the throttle doesn't allow. These also tie into the brake light circuit so that brake lights off allows, brake lights on disallows. An ON, OFF, ON switch can be used to provide the automatic controls on one side of ON with a manual override from the other ON with no activated controls at the OFF station.


A simple system can be devised by putting a pressure sensitive switch like the old Ford's and Chevy's used for brake light activation into a simple circuit by installing the switch into the 4th gear pressure passage that currently ends with a plug. This can be the other ON terminal of the main switch. This will allow lock up only in 4th, while not working the brake application issue assuming that usually isn't much except to adjust speed for slowing traffic. As soon as the transmission down shifts the pressure switch opens and the lock up removed. Lock up is inhibited hydraulically by the valve body when the transmission is in low or reverse. Since these pressure switches fail normally to off it that switch quits you can use tha manual side to get lock up till you can replace the switch while the OFF position simply stops activation no matter what. You can also use an OFF, ON, ON switch but I don't recommend these as while ON position 1 is independent; ON position 2 also includes ON 1 so the circuits lose independence. That can be restored with a suitably sized diode to prevent feed back so each one has some independence but that eliminates simple while introducing another failure possible part.


Ground happens inside the transmission at the solenoid. The computer controlled transmissions tend to work on the ground side, but the 700R4/4L60 no E is conventional 12 volts in with ground through the body.


Bogie
 
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