700r4 .electric or hydraulic lock up?

what are you using? and why.

We used a 700 behind a 383 stroker in a T Bucket. It was pretty awesome. We used a converter for a 4 cyl s-10 truck. Behind the 383 it stalled at about 2500. Then we had the electric lock up. It was wired so that if the toggle switch on the dash was flipped it would lock the converter as soon as it went into OD. Tap the brake and it would unlock. We used a cruise control stop light switch for a mid 70s GM car. So we had the low 1st gear, good stall and the OD with a lock up. Used a 3:73 rear. It would get about 23 miles to gallon cruising the highway.

vacuum

l am using the vacuum switch on mine.

the vacuum line runs from the carb to a electric/vacuum switch. the lock up happens when the vacuum hits a certain psi and disengages when l step on the brake. there is a switch on the brake pedal with 2 wires, one running to the vacuum switch and one to the fuse box, hooked up to ignition power.

works great. l have had this setup since 1999 with no problems. l prefer this over the toggle switch because everything is set it and forget it. it kicks in and out by itself, very convient.

l want to put the new hydraulic style in the next rat to see how good it works.


Later

Vacuum switch

On my wagon, I wired the lock-up through the old cruise-control on/off switch because I have no electro-hydraulic switches in the transmission, then through a brake switch, then to a hi/lo vacuum switch from an early 80s GM pickup, then to the transmission. The key is to plumb the vacuum switch to ported vacuum so that when you let off the gas, the converter unlocks. You don't want the converter to stay on when you are coasting because it doesn't have the clamping force to hold back like a standard transmission, and at lower speeds the car will buck.

If I ever get around to it, I'll put a 4th gear pressure switch in so I don't have to remember to turn off the converter at lower speeds. Right now it will lock up in second gear if I don't turn it off.

I'm putting a stick in my truck.

440shorty

The 700 is my fav tranny & I use an electric lockup.

BoB

Tripper said:

The 700 is my fav tranny & I use an electric lockup.

BoB

Click to expand...

did you wire up your own or did you use a kit.?

glad someone asked this question,,, i need a diagram to wire my 700r4,, i use to have one but ilost it, i havent used a auto in years, i am a striaght shift guy, but this build is to sell , and you would be surprized how many people dont like straight shifts[S and i need cartoons to understand how things work!

Here is a link to some good info on the 700r4

More than you need but some good stuff and you asked for cartoon version.

I have a 700r4 myself that I am not sure what direction I am going to go with it yet. May just put it in and run it......

http://purplesagetradingpost.com/sumner/techinfo/700R4p1.html

Don

i dont understand the brake light switch part!

if you dont want a togle switch to for get about turning on and off use this vacume switch where it is. standard motor products # vx3. the brake light switch breaks the ground when the brakes are aplied. its a 4 prong switch for cruise control/lock up

On my 39 Pontiac coupe,I used the info they used to have in bowtie overdrives free. I dont think the same info is available free anymore. It showed how to rewire the electrics in the valve body on a typical 700R4. It showed how to wire the 4th gear pressure switch that also energized the lockup to the torque converter.It works awsome!!I also connected it to a cruise control brakelight switch to deactivate it.I get just under 24 MPG driving the thruway at 70 mph.I clocked it a couple times driving to the Syrcuse Nats.