Hello, I am having troubles with my 700 r4. The car was bought witout a motor and the torque convertor was in the back hatch. The Vss was removed from the transmission for some reason. Okay, I have three speeds how do I get overdrive? I am not using the ecm because im using a carbed motor not tbi is that okay? How does the O/D work. Wiring and advice to setup the torque convertor and wiring it up appreciated the harness was butchered also so color specific appreciated thanks.

You shouldn't have to do anything at all to get O/D, the only thing electrically controlled is the torque converter clutch.

Where is this and how does it connect through the car and the transmission? What makes the TC lockup?My inside and outside wiring has been screwy thanks.

It connects through a 4 pin connector on the left side of the transmission.

after that where does the 4 pin connector go to before stopping? What controls the lockup?

One pin gets +12v from a switch on the brake pedal, which cuts off power when the brakes are applied. One pin goes to the ECM, which locks the TCC by grounding that pin.

There's also a third pin that tells the ECM that the transmission is in O/D, which isn't directly relevant to the TCC operation. The fourth pin is blank.

on a similar note where is the nuetral safety switch located at? I figured out the 4 pin thing but.....trans was not in it when we got it so....

the nuetral safty switch is in the passenger compartment under the shift level plate.. i believe it is on the passenger side of the shifter.

An interesting note is if the transmission was a fuel injected one before you got it, then the TV cable may be to long to work on a carbed engine (I found this out myself when i got a transmission out of an FI car. the TV cable was a few inches to long)

Okay I am not using the tbi setup and am using a carbed motor my ecm is still hooked up but i have the fuse out. What does the ecm use to determine when to lockup the tc? The vss? Do I need have the tc setup to lockup or can I leave it alone? Thanks alot with the 4 pin info.

Your ECM won't be able to lock up the TCC now, you'll have to do it another way. You could get one of several kits available on the market, or you could do it yourself with a manual switch or a handful of parts from GM.

now remember.. that is a handful of parts... lol.. so you will need to give them your full hand...lol

Better than an arm and a leg. All you need is a vacuum switch and a pressure switch for the valvebody.

thats true.. need that arm an the leg for other more fun things.. like actually driving the car lol

So which would be better a manual switch described in the techboards or the other two switches you listed? Thanks alot for the info. The trans needs some new fluid and the filter changed because it hangs and shifts hard like its sticking should the bands be looked at also? It has to be coaxed into shifting.

is the tv cable adjusted properly.. i know that can affect the shifting a bit... after that there aren't to many good senarios....

A manual switch will work fine, as long as you don't forget about it. The vacuum switch and pressure valve is probably a better idea, but slightly more difficult to do.

So when does locking the Tcc become important? When in O/D? I bet its the TV cable because it doesnt like to down shift the kickdown cable is out of adjustment so I bet the tv cable is too. When I shift into to park it doesnt always go into park it takes a stab or two. So I bet its that. The trans has been setting inside of the car for a few years so the fluid might have gummed up.

the odometer only shows 74000 miles. The orginal owner took the motor out sold it to another teenager and the parents never registered it the grandfather was suposed to be building a motor for it, but they were moving and sold it to me for 500 dollars and I got a 350 from a friend of mine in drag racing that he had built but had no use for it. So the trans just set.

TCC operation is especially important while cruising in O/D.

The TV cable combines the functions of the detent cable and vacuum modulator on older transmissions, so it's a little more complicated.

My cousins 350 turbo has a vacuum modulator thats screwed up and hes having the same shifting problems as my 700r4 it seems after it shifts up and down through the gears a couple of times it seems to shift easier. but the first time shifting through the motor stores rpm and then jerks as it shifts like its hanging. So does the TV cable sound like the culpret? The car was tbi and now i have a 4 barrel holley 650. How do you recommend fixing it?

Set the TV cable properly to start with. There's only one correct setting for it, it's not an adjustment in the sense that you can vary it to make it do what you want. If the transmission still doesn't behave after that, it might be time to dig deeper.

are you using the same cable that was originally on the car with the TBI setup? ifso... that cable is a little to long ( same problem with mine. i ordered a new one for the carbed versions.. there are universal ones that do work.. but if you use the oem one.. the tbi is about an inch longer than the carbed one. (i know from expereince since i got a 700r4 out of an 88 tbi car and put it into my 83 carbed motor and the cable was waaaay longer than what could actually be adjusted right.

What about one from a salvage yard? I found a v6 and a v8 camaro both carbed with transmissions. Could a TV cable from one of them work?Could I have a example of an aftermarket kit for the Tcc or a link for a store? Thanks

From summitracing.com:

<A HREF="http://store.summitracing.com/partdetail.asp?autofilter=1&Ntt=700R4&N=302428&part=PRF%2D60109&autoview=sku&Ntk=KeywordSearch">Painless Wiring 60109</A>

<A HREF="http://store.summitracing.com/partdetail.asp?autofilter=1&Ntt=700R4&N=310473&part=TCI%2D376600&autoview=sku&Ntk=KeywordSearch">TCI 376600</A>

<A HREF="http://store.summitracing.com/partdetail.asp?autofilter=1&Ntt=700R4&N=400004+4294844569&part=BMM%2D70244&autoview=sku&Ntk=KeywordSearch">B&M 70248</A>

if you find a cable from a carbed 305 then you should be good to go. a v-6 model is to long.... (there are way more cables than i figure there should be.. but there is a different size for all of them depending on engine size and intake config... not very foresighted of gm... but ya know... what can ya do now other than buy a new one for it, or find one in another car that is carbed with a v-8

Yea i think i found one at a salvage yard. Basically the manual switch is the cheapiest instead of a kit. So when I shift into 4th gear then I should flip the switch ,will it lockup in any other gears ,and will it downshift still? Can I have a basic senario?

If the switch is on, it will lock up in every gear except 1st and reverse.

And thats okay right? When I come to a stop light do I have to flip the switch off or can it just stay on? It will still shift though right?

It's ok, but not desirable. Shifting will be fine, but it will bog on every shift at part throttle, especially on the 1-2 shift. It will unlock when it downshifts into first while stopping, although there's a chance that it could stall in a panic stop if you don't wire it through the brake switch.

Hmm what do I need to do to make the other two switches work?

I have wondered. and Apeiron seems to be pretty knowledgeable.. Exactly how does the switch work to lock up the TC? I have had the pan off and looked at the valvebody and can not figure out how it does it's job. (I can see where the 3 wires come in.. and the assembly, just have no idea exactly what it does to lock up the tc)

The only "difficult" part about using the vacuum switch and pressure switch is dropping the pan and replacing the factory 4th gear switch. Apart from that it's just a little bit of wiring. It's no different than what you'd have to do to install an aftermarket kit.

The stock 4th gear switch doesn't have anything to do directly with the TCC operation, it only tells the ECM that the transmission has shifted into 4th gear. Based on throttle position, manifold vacuum, vehicle speed, and who knows what else, the ECM sometimes may decide to lock the TCC.

The TCC apply fluid circuit in the valvebody takes pressure from the 2nd gear circuit, so the TCC can be applied any time the transmission is in 2nd gear or above. Normally this pressure is exhausted, so that the TCC isn't applied. When the ECM grounds the TCC solenoid, a checkball blocks the exhaust passage so that the TCC apply pressure can rise and engage the clutch.

Can you list the steps in order? What do you replace the 4thgear switch with? Any particular place to get these switches without buying a kit?

ooh. so that bit there for that some of it has been rendered non working when i removed the CCC carb and such (no wires are plugged into the engine any longer at all...

Both switches are available from GM.

Replace the NC 4th gear switch with a 8642473 single terminal NO switch, and connect the wires to pins B and D together inside the transmission. Outside the transmission, cut the wire to pin D and connect a 14014519 vacuum switch between the cut ends. Connect the vacuum switch to a ported vacuum source on the carb.

If you do it this way, you can also still install a manual switch through the ALDL as described in the tech article on this site so that you can lock the converter up manually if you want.

Any ideal on the prices of the materials? I have a windshield I need installed($60), getting the transmission fluid and filter changed the bands looked at and adjusted($69.99), getting a replacement back brake light cover($10.00), buying paint for touchup and ground effects($20.00).I'm only 17 and my dad is getting tired of pitching in money. Plus a TV cable, shifter cable, and kickdown cable.

Off the top of my head, at worst the vacuum switch might be about $40 and the pressure switch about $20.

While you're in the transmission you'll want to replace the fluid and filter as well.

Okay thanks I'll show my dad.

if anyone is interested in doing this mod to tranny here is pricing. first one is local gm dealer
5.85 for 8642473
43.86 for 14014519

here is prices for www.gmpartsdirect.com
3.40 for 8642473
25.21 for 14014519

there is also $10.63 handling (which is to OH not sure about west coast) but unless you need it fast you are better off ordering online. total for both with shipping is still cheaper than dealer price on just vac switch. Hope this helps someone out.

Sorry to dive in on your post, but I'm currently putting a auto in a manual car. Basically you guys are saying if the 4 prong plug on the 700r4 is not connected to anything, then the convertor won't lock up? To fix this you can either buy a kit, use the gm parts or wire a toggle switch. Couldn't you just use the toggle switch and wire up a safety switch to your brakes so that the power to the lockup is killed when the brakes are applied?

Another thought, isn't the stock stall around 1600-1800? If this is the case then the car wouldn't tach much lower with it locked up as apposed to it being stalled, right? Ofcoarse, this would all depend on gear ratio I guess.

Right

You could, as long as you can remember to lock and unlock it.

There's a change of something like a couple hundred RPM. The important part is that when locked up flow through the cooler is maximized and shearing of the fluid in the torque converter is minimized, which greatly reduces heat.

just a question as long as we are on the 700r4 thing . How firm should a tranny shift from the factory? Pretty firm shift it nothing has been done to it and it has low miles? I adjusted the tv cable and it appears to be right, but wow talk about firm shifts...

another thought also to help reduce damage to the tranny is using type F fluid. yes it is a Ford product but it is better than dextron fluid. try it, it really does help firm up shifts also. great cheap performance tip.

Type F has different friction modifiers in it to work with older automatics that used asbestos clutches. In a paper-clutch automatic like the Hydramatics it will firm up the shifts, maybe even without hurting anything.

Whatever you do, just don't waste your money on the B&M Trick Shift garbage. It's plain old Type F with blue dye added to make it purple.

my thoughts exactly I have heard pretty decent reviews on royal purple's stuff though.

well, I've decided that on my application I'm gonna wire up a switch to lock up the convertor directly through the plug on the tranny, since my car was a manual. I'm gonna use either a cruise control or brake safety switch to route the power to a toggle switch, then to a relay and on to the plug on the tranny. Then I'll just ground the other wire so that when I flip the switch the convertor locks up, but if I hit the brakes the power will be killed and unlock the convertor. Hopefully this will allow me to save gas, keeps temps down and not have to get an auto wiring harness. Since I plan on putting the T5 back in this winter after I rebuild it. Hopefully this thread has helped out the guy that started as much as it helped me. Thanks all.

Excellent thread - Very Helpful.

My '85 Camaro was a 2.8 fi with 700R4. Now its carbed V8 with a different 700R4. Can anyone tell me if it's possible to have the ECM control the TCC as it used to?

Otherwise I will probably do the same as smnitWS6TA. What kind of relay did you use?

Thanks,

Andy

Not really.

Why? (not arguing the point - just trying to learn something) It seems like I still have all the parts to do the job - ECM, VSS, brake pedal switch. I suppose it is more complicated than that...

Without the inputs it wants, the ECM won't do much of anything.