View Full Version : Tranny electronics?
I'm swapping a turbo 700r4 from a 1983 1/2 ton into a non computerized rig. Anyone know about the electronics requirements for it, and how it would work without it. Thanks.
08-02-2000, 01:41 AM
I'm no expert by any means. From what i understand on the 700R4, the only thing computer controlled on that transmission is the lockup on the torque converter.<br>The transmission that succeded the 700R4 is the current 4L60-E which is completely electronically controlled,<br>That's about all i know, i'll let the experts take it from here.<p>Tim
OK guys, there are only three wires running into the tranny; yellow green and blue I believe. Any gear heads know which wire goes where in the computer? The only other control other than the shifter is a cable which I have determined is for the kickdown from my shop manual. Thanks a bunch.
08-08-2000, 01:22 AM
i have an `86 1/2ton 4x4 with a 700r4. And those wires are only for the torque converter lock up. it will run fine without those. mine were disconnected when i bought it. just don`t do alot of interstate/long distance driving with out the torque converted locked, it will cause the fluid in the converter to get hot and burn. i just had to replace the tranny. Make sure your 700r4 has been beefed up a little. they are known for dropping easy. and i suggest an external trans-cooler. they are cheep and keeping an automatic cool is important. frahmie
08-10-2000, 11:30 PM
MTCK,you say its out of an 83,is this a CCC system with a feedback carb?it will have a check engine light and a blue connctor on the carb that ticks with the key on.If it has both of these,and I think it does,it is an external lockup transmission,if it has neither it is internal lockup.if its internal lockup,all you need to do is supply +power to the lockup solenoid,to tell which one it is drop the pan and follow the wire to the solenoid to be sure.I think its an external lockup setup and to make this work easy you need to find the +wire for solenoid,that will need to be run into the cab and thru a brake switch,that is open in the brake position and closed while off the brakes,you can pickup power from the fuse box for the brake switch,it really doesnt matter if its hot all the time or key on.Now the other 2 wires,one is the ground for the lockup solenoid,you will take thisover the top of trans to other side,now there are 2 1/8 NPT fittings on the side of trans just above the trans pan mounting surface,one of those tee's into the 4th gear oil supply,you can buy an oil press switch for an early 80's 3.8 liter buick regal,it has 3 positions on it,you need to find the 2 that are closed with pressure applied,hook the ground wire from lockup solenoid to one side of switch and take a small wire and go from the other post to ground somewhere on trans.what this will do is apply lockup whenever you are in 4th gear,and disengage it whenever you step on brake pedal.if you use the wrong 1/8 fitting it will lockup in 3rd,no big deal,just put it in other one.if you use wrong posts on switch its no big deal because u r on the ground side and nothing will short out,it just wont work,try a different pin.I can get the schematics to tell you what wire goes wher,but i neeed exact year,model,engine size,series,etc and a couple of days to get it.Do not run this without lockup in OD if you want it to last,if you have a tall ratio rear end the slippage will be enough to toast your trans even with a cooler,the lockup is needed because the overdrive gear brings the engine speed down and this causes more slippage than with the old 3speed autos.The most important part of the job is getting the correct kickdown cable adjustment,if its to loose you will burn up trans from low line pressure,I guarantee the 3-4 clutch pack will fry if you do this,try to get the brackets from donor vehicle and hopefully they both had Q-jet carbs.these transmissions are good if properly setup and installed,but you need to get full detent on the kickdoen cable if you want it to live,because they have no vacuum modulator so this is the only way for the trans to see the load being placed on it and up the line pressure,and shift points accordingly.Good luck
[Edited by John DiMartino on 08-11-2000 at 02:40 AM]
Thanks for all the input guys. John, I appreciate all the time you put into your reply, and I was just starting to play with your suggestion when a friend who was over helping with the project (ie, sitting in the garage reading a Summit catalog) pointed out that Painless Wiring sells a kit to control the lockup on non computerized vehicles with this transmission. It includes a 4th gear pressure switch, converter lockup solenoid, vacuum control switch, wiring harness and new gasket. $120, but pretty easy to hook up. I think I'll go with that, since this is a $1600 tranny. Fairbanks racing automatics built it, out of Stratford CT I believe, and I was very happy with it in my old 83, before I wrecked it. Also has a cooler about the size of a honda's radiator, and a temp gauge for it. Really glad I found this kit, so not to take the big time $$ gamble. Thanks again for all the input.
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