I am ordering a 700r4 and no one seems to do it one way, it's all different.

one shop reccomends a hydralic switch, "hassle free" set it and forget it.

the other shop wants to charge me for a manual switch. and solenoid in the trans.


somehow i think somebody is trying to get one over on me.

I have a manual car, I looked at the bin files for an automatic car and without a doubt I can use those settings in my manual bin to control lock up

so eventually I WILL utilize this feature,

however .....

meanwhile to get on the road i will trigger the lockup with a switch

so tell me, what do i need to turn the lockup on in 4th at higher speeds and not lower speeds?

should it not lock up in 1st 2nd or 3rd?

should i have a brake override, and will this "cycle" on and off as per the brake pedal?

what is a vacume switch for

I am lost any clearity would be great!!!

 

Sometimes you may want to use lock-up in third gear to reduce the convertor heat build-up. You may want a vacuum switch that will unlock the convertor at WOT so it does not destroy the lock-up cluch. Most convertors were not designed for WOT operation in lock-up mode.

 

Run away from the guy who wants to charge you for a lock up solenoid. It is already in the tranny and all 700R4s have them. If you want to keep it simple, all you need to do is ground the torque converter lockup wire going to the tranny. A $3.49 Radio Shack switch on the console will do fine. The converter will not lock up in first gear due to the hydraulics in the tranny. You can manually lock it up in 2nd, 3rd, or 4th. I used to lock mine up on the freeway, sort of like a fifth gear when cruising. The vacuum thing is if you want to set the tranny up so the lock up comes on automatically during high vacuum situations.

 

So you are saying I don't really need even a solenoid in the trans I can just run a switch directly to lockup wire.

would it not be easier to have the 4th gear ( i suppose they are on the trans as well) pressure switch tell the solenoid to ground the lockup wire?
then i guess it would always be in lockup in fourth and have an overide brake switch to disengage the lockup, when the brake is used.

do you think this would cycle the system on and offf too much?

is there a better "SCENARIO"

 

As you intend at a later date to go to stock type ECM control I would set up trans as per stock.Install the brake switch and stock plug with wiring back to the dash
For temporary operation
Run a switched 12V to the brake switch ( will need that anyway for permanent install ) and ground the tan wire through a switch which then gives you manual control of TCC with the automatic disengage when you hit the brakes.
Then when you come to hook it up for ECM control ,all you need to do is run the tan wire to the correct terminal on the ECM

 

Thanks you always come through, we went through this the last time except the pix disappeared. and i never retain the information

my current brake pedal already has 2 switches, 1 for the brake light and the other to disengage the cruise control are you telling me the automatic car are fitted with 3 switches under there?

additionally this scenario you have suggested, is stockish... sans ecm.

so please confirm for me that if wired to the ecm, in some conditions while in 4th gear, could cause the ecm to disengage the TCC, and if configured the way you mentioned( taking out the ecm and putting a switch in it's place) will automatically go into lockup with the circuit grounded and never go into lockup, with the curcuit open, correct?

and when the brake switch open the TCC disengages as long as the brake is applied, until it slows the car to downshift to 3rd in which, in that case it would never lockup, since the 4th gear pressure switch is not tirggered...right?

is the pressure switch and the TC solenoid one piece? and not separate components?

any pics?

again thanks

 

Correct

Only if you wire it so TCC only in 4th gear.As noted with stock setup TCC can be engaged in other gears

2 seperate items

I recall the switch has 2 sets of contacts;one is N/O the other N/C so that when you brake the stoplight comes on and the TCC goes off or vise versa
The cruise release is a vac switch; rubber hose runs to it

 

I'm not exactly clear on what outcome/effect you want to achieve...is it to lock up the TC when it would otherwise not be locked up or to unlock the TC when it would normally be locked up? Just to add my 2 cents, the effect that I wanted was to keep the TC unlocked when it would normally be locked up. Reason: I find that my '85 locks up too early and won't unlock early enough. (i.e. stays locked up at too slow a speed for my liking especially when cruising in the city or climbing hills). I wired in a toggle switch to 2 of the 3 wires at the brake switch (can't remember which too, but I can look in the spring when the car comes out of storage, if you need me to). This allows me to override the lock up, similar to touching the brake, and keeps the TC unlocked until I switch it to normal mode and it locks up as per the ECM parameters. If it is locked up, I can flick the switch and unlock the TC whenever I want to. There is some caution with this set up in that extended driving with the TC unlocked when it would normally be locked up puts additional stress on the transmission because of heat build up due to the clutches doing all the work. I've had this set up for a year now, and am very pleased with how it works.

 

Thanks again, the one electrical switch on the pedal has 2 functions, that is good to know, I'll just put it in the auto pedal when I do the switch over.

so you are saying the defualt factory settings are the TCC will lockup 2,3,and 4th gears within the ecm paramenters.

isn't it that the 4 gear pressure switch is the master switch? then how is it that the solenoid will know to go to lockup in the other gears, are there more pressure switches in other gears?


In that case,I think I will just leave the ECM out of it and just keep the switch and trigger it on quiet freeway cruises, anything that requires aceleration and stopping and going and decels, I will have it turned off and with the brake switch invloved, this could "optimize" the TCC while it is ON VS. how the trans builder wanted me to have it on or off without braking release,

my guess is GM put it there for a reason. and to recommend otherwise really causes me to doubt his intergrity or sincerity.

since pletzvet thinks it goes to lockup all the time; personally from what I have been told it sounds like his TV is not set correctly letting it go into 4th too soon, of course this is my guess, and fear that the automatic will go into wrong gears and can't get out of them.

 

since pletzvet thinks it goes to lockup all the time; personally from what I have been told it sounds like his TV is not set correctly letting it go into 4th too soon, of course this is my guess, and fear that the automatic will go into wrong gears and can't get out of them.[/QUOTE]

I take it that you are replacing your manual trans with an auto? If so, then you might find that the switch on the brake pedal isn't equipped for an auto. Thanks for sharing your thoughts about a possible TV problem and too early into 4th, however, I checked the specified speeds for all up shift points (under normal driving conditions) and it is right on spec. I had wondered if the TV wasn't working properly but apparently it is. The desire to control the lock up/unlock comes mainly from personal preference.

 

Millions of cars had non lockup convertors (TH400 / TH350/etc ) and had no problems.The lock up feature was installed to save gas.When running unlocked , the convertor still has a certain % of slippage which causes heat .
The clutches are still taking the same load whether the convertor is locked or not
The problem with T700's presents itself with the early models which only had full fluid flow to the trans cooler when the convertor was locked.
This is where the "running the convertor unlocked will kill your trans" stories come from. This was changed in the later models to give full flow all the time