TCC Lockup -- By Manual Switch?

[ford4wd08]

I'm struggling with how to handle my lock up of the TCC on my first year A4LD.

I have done the duraspark withe HEI module and removed the computer.

I tried the pressure switch method and failed horribly, so I don't think I'm willing to drill a hole into the case of my trans again.

So I know that there is a 12 volt signal sent to the 2 wire connector on the trans. Then the ECM would ground the circuit to activate the TCC.

I have since ran a keyed hot wire to one side of the solenoid. I know I can add a manual switch to the dash to ground it, but how practical is this?

Is it basically every time you get on the highway above 50 mph you flip the switch? What If you forget to flip it off or have to come to a sudden stop?

Is there something that you could wire that when you hit the brake it would open the circuit and unlock it again?

I'm considering all options and I'm willing to rob more GM parts to make it work lol.

And yes I have read the Tech Section article, but it is very difficult to find the GM vacuum switch these days from what I can find.

 

[ford4wd08]

I'm tempted to try this as well.... I think I had posted it in an earlier thread.

https://www.jegs.com/i/TCI/890/CMP3766B/10002/-1?parentProductId

 

[ford4wd08]

Here is an option as well.

https://www.amazon.com/Superior-K058-Universal-Adjustable-Vacuum/dp/B0778KLW7H

 

[RonD]

I think you would be better off with a speed switch vs vacuum switch

Like this one: https://www.coloradospeed.com/pcm-tuning-c-2902_1734_1871/lingenfelter-stov004-vehicle-speed-based-switch-speed-to-voltage-converter-p-8400.html

Expensive but would do what you need, ground TCC solenoid above any speed you like, and unground below that speed

You can add a VSS to trans or transfer case if you don't have one already, looks like this: https://www.therangerstation.com/tech_library/images/speedsensor.gif

Can be found at any wrecking yard on 1997 or earlier Fords, a speedo cable/VSS combo unit, or you can get new

 

[ford4wd08]

I think you would be better off with a speed switch vs vacuum switch

Like this one: https://www.coloradospeed.com/pcm-tuning-c-2902_1734_1871/lingenfelter-stov004-vehicle-speed-based-switch-speed-to-voltage-converter-p-8400.html

Expensive but would do what you need, ground TCC solenoid above any speed you like, and unground below that speed

You can add a VSS to trans or transfer case if you don't have one already, looks like this: https://www.therangerstation.com/tech_library/images/speedsensor.gif

Can be found at any wrecking yard on 1997 or earlier Fords, a speedo cable/VSS combo unit, or you can get new

Ah the infinite wisdom of @RonD

I was thinking in my mind oh how to do a speed switch, but didn't know how to make that into a voltage.

I will gladly pay the $130 if it works properly. And it looks like it would be a much, much more reliable system.

Time for a little more research.

 

[ford4wd08]

@RonD

I believe this is an option for a VSS correct?

https://transmissioncenter.net/shop/ford-8-pulse-speed-sensor-and-speedometer-cable-drive/

 

[RonD]

Yes, that's a new one

Check if you already have one, I doubt it on a 2.8l but maybe
Ford was adding VSS for cruise and computer use in the 1980's

You will need to get the plug-in for it, as said wrecking yards will have the unit and the plug-in, but plug-in is available new as well

 

[ford4wd08]

Yes, that's a new one

Check if you already have one, I doubt it on a 2.8l but maybe
Ford was adding VSS for cruise and computer use in the 1980's

I don't believe I have one, but I'll confirm. I don't remember it looking like that when I had it out before. I do have cruise control, but I believe it is all independent of the Computer controls.

 

[RonD]

Yes, the older cruise systems use speedometer cable IN from transmission and then OUT to speedometer
And they did have a pre-cursor VSS inside, but not usable for this application, lol

 

[ford4wd08]

Yes, the older cruise systems use speedometer cable IN from transmission and then OUT to speedometer
And they did have a pre-cursor VSS inside, but not usable for this application, lol

Thanks for the great info as usual.

It is a little costly to implement, but not horrible. It will be much better than having a system that doesn't use the TCC. And I can control precisely when I want the TCC to lock up.

I just want my Bronco back and to be able to drive the thing!

 

[RonD]

You can still add a switch to disable TCC when you want, I would add a RED led on this switch so you know its OFF

Reason being is driving habits, you can set TCC for 35MPH for example, if you were to "Floor it" at 40MPH you would not get as fast an acceleration with TCC locked, because there is no "throttle sensor" to deactivate it at WOT(wide open throttle)

It's a small thing, not a big deal, just depends on what YOU want

TCC is strictly an MPG and heat thing, when TCC is locked you get best MPG and because torque converter is no longer "slipping" it, and transmission, runs cooler

 

[ford4wd08]

You can still add a switch to disable TCC when you want, I would add a RED led on this switch so you know its OFF

Reason being is driving habits, you can set TCC for 35MPH for example, if you were to "Floor it" at 40MPH you would not get as fast an acceleration with TCC locked, because there is no "throttle sensor" to deactivate it at WOT(wide open throttle)

It's a small thing, not a big deal, just depends on what YOU want

TCC is strictly an MPG and heat thing, when TCC is locked you get best MPG and because torque converter is no longer "slipping" it, and transmission, runs cooler

I was thinking about the switch as well as a fail safe, in case something else went wrong. I could turn it off and on as need be.

I am thinking of having the TCC come on at 45 or 50 mph, but I will have to do some trials and see how it works.

 

[RonD]

sounds good

Its all about how YOU drive, computer control was set at factory so no user changes, later models had adaptive "learning" for driver habits, cruiser or racer, lol

 

[ford4wd08]

sounds good

Its all about how YOU drive, computer control was set at factory so no user changes, later models had adaptive "learning" for driver habits, cruiser or racer, lol

Makes sense. I just want my Bronco back so I can work on it... Jeez I really hate shops.

 

[ford4wd08]

link for later.....

https://www.lingenfelter.com/product/L460340004.html#.XyhAvChKhPY