700R4 lockup alternatives

Topsterguy · March 14, 2005, 01:19:51 AM

Hi All! I'm using a 700R4 trans in my coupe and need opinions on the best lock up system to use -electric or vaccuum? I had the vaccuum setup in an F-100 I did but it would cut in and out all the time which was a PITA! What are the alternatives and what's the best? Thanks again ahead of time! Larry

jeffa · March 14, 2005, 02:14:44 AM

Quote from: "Topsterguy"Hi All! I'm using a 700R4 trans in my coupe and need opinions on the best lock up system to use -electric or vaccuum? I had the vaccuum setup in an F-100 I did but it would cut in and out all the time which was a PITA! What are the alternatives and what's the best? Thanks again ahead of time! Larry

Hi Topsterguy:
I jumped on the web as I know there are a lot of companies that offer electronic control modules for these transmissions.
To quote one of them (http://www.novak-adapt.com/knowledge/4l60e.htm); "Earlier engines can be joined to the 4L60-E by use of a GM Controller, #12497316. Carbureted engines will require a Throttle Postion Sensor."
I would assume there is a similar part for the 700R4.
This guy ( http://www.smokemup.com/tech/700r4.php ) includes a wiring diagram for a manual lockup control. I would advise against this, as he says, it's easy to forget it's locked and "bog" the motor.
Or here; http://www.tciauto.com/electronics/
Best idea: just jump on the web..

ram-rod · March 14, 2005, 07:30:12 AM

there was an article in a 4x4 mag. The guy had a manual over ride, in the form of a dip switch, on the floor. I think he was having trouble, with up/down shifting. Also it was a cheap way out for him.

rumrumm · March 14, 2005, 08:15:38 AM

Here is another alternative. I had mine built with a hydraulic lockup like the one at www.project33.com . Click on transmission and read up on it. It is all done internally. My tranny guy told me the only drawback to doing it this way is that lockup is immediate, but with an engine with a lot of torque, I would not notice.

enjenjo · March 14, 2005, 08:45:04 AM

I set them up with an internal lock up too. The instructions are here. http://purplesagetradingpost.com/sumner/techinfo/700R4p2.html

All the parts you need are usually already there. I believe this locks up in third and fourth only.

Crosley.In.AZ · March 14, 2005, 08:56:10 AM

often the vacuum cut out setups do not have the delay valve in the system.

GM used a delay valve so the vacuum did NOT drop quickly at the switch. This would avoid the converter clutch searching in & out of lockup.

I do not care for the vacuum switch setup.

Topsterguy · March 14, 2005, 08:57:09 PM

Great! Thanks again Guys!

lobucrod · March 16, 2005, 09:18:45 AM

Quote from: "Topsterguy"Hi All! I'm using a 700R4 trans in my coupe and need opinions on the best lock up system to use -electric or vaccuum? I had the vaccuum setup in an F-100 I did but it would cut in and out all the time which was a PITA! What are the alternatives and what's the best? Thanks again ahead of time! Larry

I've been running a 700 r4 in my 38 Chevy coupe for 3 years with the vacuum switch and it works great. I have a GM vacuum switch hooked up in series with a normally open switch on the 4th gear pressure port. I also have a pressure switch on the 3rd gear port hooked up to a toggle switch so I can make the convertor lock up in 3rd if I want it to. This helps since I have a high geared versailles 9" rear. If I'm in lots of hills or cruising below 70 with a group I can drop the tranny to 3rd and flip the switch. This keeps the tranny from heating up. I recomend a tranny temp gauge. I'm using one made by B&M.

jeffa · March 16, 2005, 10:31:18 PM

Quote from: "lobucrod"
Quote from: "Topsterguy"Hi All! I'm using a 700R4 trans in my coupe and need opinions on the best lock up system to use -electric or vaccuum? I had the vaccuum setup in an F-100 I did but it would cut in and out all the time which was a PITA! What are the alternatives and what's the best? Thanks again ahead of time! Larry

I've been running a 700 r4 in my 38 Chevy coupe for 3 years with the vacuum switch and it works great. I have a GM vacuum switch hooked up in series with a normally open switch on the 4th gear pressure port. I also have a pressure switch on the 3rd gear port hooked up to a toggle switch so I can make the convertor lock up in 3rd if I want it to. This helps since I have a high geared versailles 9" rear. If I'm in lots of hills or cruising below 70 with a group I can drop the tranny to 3rd and flip the switch. This keeps the tranny from heating up. I recomend a tranny temp gauge. I'm using one made by B&M.

Correct me if i am wrong, but if you have a 4-speed auto, and you can have lock-up on 3rd and fourth, or unlocked on 3rd and 4th (well, all gears), doesn't this mean you actually have 6 gears?
In my street car (Commodore (GM) with with a 4L60E) we have a "power/economy" switch, which alters the shift points. I installed a button on the floor that is wired in parallel to the power/eco button. The idea is, if I am accelerating moderately at about 50mph and the convertor was locked (economy setting), presing the button (with my foot) selects power, and even though I don't press the accelerator any further, the torque convertor unlocks and the car accelerates much quicker. - It works better in practice than it sounds here. It's also good when coming out of a corner and I need a little extra power, but not into kickdown. Press the button and the transmission either unlocks the torque convertor or drops into third.