Ok, I know this is like beating a dead horse, but everyone says there are tech articles on here as to how we are supposed to set up the tranny so it works properly.

Original
1984
2.8L CC-Carb V6
700R4

Now
Non-CC Carb V8 350 With HEI
700R4

If anyone can point me to the Tech Article I would Like to know how to get the TCC Lock UP to work properly with this setup.

I have found a few of these

http://www.tpiperformance.com/noncomlockit.html

Was hoping it could be done without buying a kit. We had to buy one for My Brother-In-Law's 280Z when we put the 350/700R4 in it. Was realling hoping there would be some way to use the existing computer inputs for it to work properly.

 

Here is another one from Summit Racing.

http://store.summitracing.com/partde...art=TCI-376600

 

https://www.thirdgen.org/newdesign/t...ueswitch.shtml

 

Wait a minute, you said "work properly".

This will just get it to work manually.

 

Yeah I was hoping to Avoid the Manual Toggle. This will be a daily driver and I'm Hoping to get it to work on its own so I don't have to worry about forgetting whether its on or not.

 

You can get a normally open, two-pole pressure switch and replace the current 4th gear switch on the valve body. Wire the solenoid in series with this new switch, and it will lock whenever the tranny is in OD.

You could also put in a simple vacuum switch in series with the power wire so it unlocks when in OD and needing a little more umph when vacuum drops to get up steep hills.

 

Will It Hurt the transmission if I leave it just hooked into the old ecm cable until I decide on what to do with it?

 

Quick Question..

I was looking at the Tech Article Again and had a question.

One of the wires from the transmission is a 4th Gear Enable signal to the ECM right? Letting it know when the transmission is in 4th gear.

Is that signal still present even though my ECM is basically a dummy box now.

And if it is, could I just wire in a triggered switch in place of the toggle switch so that whenever it see's that voltage for 4th gear from the transmission it makes the jumper that the toggle would do manually?

 

Found this today.

GM has their own version of the lock up switch to retrofit the 700R4 to pre computer controlled vehicles.

http://www.gmgoodwrench.com/gmgoodwr...on=pp#24502513

Its at the bottom of the page.

 

The 4th gear indicator is a high-impedance (low current) 12v signal. It's always there, but without the other inputs to the ECM, the ECM isn't going to do anything with the 4th gear signal.

There's no harm whatsoever in keeping the harness connected as it is right now. The harm comes in driving the car w/o TCC lockup. Tends to burn up 3-4 clutch packs.

I'm going over all this in my mind again. The ECM locks the TCC by completing the circuit to ground for the TCC solenoid. So, what you're trying to accomplish in all this is to ground the solenoid when you want the TCC to lock. The link to the GM kit says it's a "normally closed" switch. I may have something backwards, but a single-pole, normally closed switch will make to ground until pressure is applied. That sounds the exact opposite of what you want to do.

I don't know what kind of power the 4th gear switch is rated for, but it would seem that routing the solenoid control wire over to the existing 4th gear switch (all this inside the pan, by the way) would do what you want. When in 4th gear, it'll lock unless the brake is applied (I'd still put in a vacuum switch, though). The 4-3 switch will still be in the power side, so it will unlock when the tranny shifts down (helps avoid jerkiness).

Somebody rescue me and tell us all what's wrong with this thinking.

 

Perhaps nothing:

http://www.highperformancecars.com/crosley/lockup1.htm

 

I'd just use the vacuum switch most 80-88 full size trucks and S10's use them with no problems. The part is only $22 list at the dealer and if they cant find it by name just tell them you have an 85 S10 2.8 with a 700R4 and need to replace the vacuum TQ converter lockup solenoid, heck most transmission shops stock them for use in situations like yours. It locks the converter at cruise vacuum above 14/15in cant remember exact vacuum.