6.2 IP TPS switch!

[turbovanman]

Does that switch control the trans lockup?

After putting the new pump on, I just used the existing marks, like I did with the pump before, on the way home, it was coming in and out of lockup, now it doesn't work at all. It did sit for over a year so hoping the trans didn't take a crapper, :sad:

 

[just a number]

it's easy to check and adjust. all you need is a voltmeter an patience. the are 3 wires. one is a 5 volt line from the computer. 2nd is ground and the 3rd is the return signal wire. you should see about .5v at idle up to 4.5 or so at WOT. you don't need it running but it has to be turned on. to adjust it you just need to loosen to bolt and slide/turn it a bit. make sure you go slow between idle/WOT. I missed a bad spot twice so it pays to be patient.

one thing I forgot to add. is there anything else electrical not working. Mine was tapped in with the radio.

 

[turbovanman]

Nothing changed except pump and injectors, but it sat for over a year.

I can't find info on what it does, so curious if this controls the TCC or ?

 

[iamdave0887]

The 700R4 doesn't use a TPS like the 4L80E does. The 700R4 uses the TV cable to sense throttle position.

My TPS is a switch, not a sensor. When you rotate it it'll "click" a few times on and off at different throttle positions. Mine controlled the EGR and EPR. It's long since disconnected however, and the EGR "fell off". ):h

 

[Missy Good Wench]

The 700R has a TPS that is for the Converter clutch control.

The TV cable runs the tranny throttle pressure. This controls all the shift points up and down.

Around 89 they discontinued the hydraulic controls in the VB to run the converter clutch.
The clutch was then run totally with the ECM.

The lockup clutch has always been handled electronically and the TPS is part of that system.

An older 700R (pre 89) can be outfitted with Kit from Transgo (700 LU) if a remember correctly that puts all the controls for the lockup into the Hydraulics of the VB and elminates any need for electrical hookups

A great product for sure.

Missy

 

[iamdave0887]

The 700R has a TPS that is for the Converter clutch control.

The TV cable runs the tranny throttle pressure. This controls all the shift points up and down.

Around 89 they discontinued the hydraulic controls in the VB to run the converter clutch.
The clutch was then run totally with the ECM.

The lockup clutch has always been handled electronically and the TPS is part of that system.

An older 700R (pre 89) can be outfitted with Kit from Transgo (700 LU) if a remember correctly that puts all the controls for the lockup into the Hydraulics of the VB and elminates any need for electrical hookups

A great product for sure.

Missy

Interesting. So that's why my lockup used to kick in right after it hit overdrive. It was probably improperly adjusted. Thanks MGW. I learned something new.

 

[turbovanman]

The 700R has a TPS that is for the Converter clutch control.

The TV cable runs the tranny throttle pressure. This controls all the shift points up and down.

Around 89 they discontinued the hydraulic controls in the VB to run the converter clutch.
The clutch was then run totally with the ECM.

The lockup clutch has always been handled electronically and the TPS is part of that system.

An older 700R (pre 89) can be outfitted with Kit from Transgo (700 LU) if a remember correctly that puts all the controls for the lockup into the Hydraulics of the VB and elminates any need for electrical hookups

A great product for sure.

Missy

Ok, I figured it had to be that TPS switch as the TCC is electrically controlled but wasn't a 100% sure.

Hmmm, I might have to update the trans and get rid of the electric TCC although I do like it coming on in 3rd and 4th, :thumbsup:

 

[turbovanman]

I found some info on setting it, tried it, didn't make any difference, tried the .5 volt at idle, lowest I could get was .9 volts and it still doesn't work. Finally found an old manual that describes exactly how it works so going to dig into it. I'll update when I figure it out.

 

[Missy Good Wench]

The functionality of the lockup on the 700R is IMHO marginal ay best.

Take for example, the 4L80, now this trans shifts through the 1-2 the 2-3 and the 3-4 shifts then at or slightly above 45 MPH with light throttle the TCC locks up.

This is a perfect calibration of the thing.

The lockup clutch was never meant to be engaged at low speeds.
The whole concept of the TCC is to eliminate the small amount of slippage present in the converter during "Cruise" operations.

The TCC was designed to help with mileage out on the highway, nothing more.

The construction of the TCC is pretty sketchy at best.

Inside the front of the converter housing is a cup shaped disc that fits in close proximity to the converter housing, such that it affords a fair seal between the Disc assembly and the converter housing.

The clutch disc assembly is splined to the input shaft of the transmission.
The disc has a pair of friction material areas on the front facing surface of its "Disc" one near the perifery that is about an inch wide that runs the entire diameter. The other "ring" of friction material is near the hub area in the center.

During operation "Takeoff" the supply of fluid to the converter is fed through a passage in the input shaft that directs the flow to the front of the "clutch disc" and it keeps converter full of fluid and also keeps the clutch "disengaged".

Once road speed has been reached and the converter has been commanded to "LOCKUP" Either a series of hydraulic valves and or an electric solenoid (Or both depending on the year model of the 700) redirect the fluid flow in the converter to the area just behind the clutch disc unit.

With the fluid now flowing behind the clutch assembly it casues the whole unit to move slightly forward and allows the 2 friction rings to grab the front of the converter case this locking the converter into a solid unit that eliminates all hydraulic slippage.

Sounds cool eh ???

Well the principal is very basic but the contruction of the clutch is not designed to take a great deal of load.
This is the reason that it is not recommended to use the OD setting when towing.

The OD places a lot more torque requirements on the converter clutch to keep the vehicle moving.

During hard pulling the tiny areas of clutch lining can start to slip some. As slippage continues over time the clutch lining wears and in some cases the slippage is enough that the lining burns and goes away entirely.

Once the lining is gone the clutch plate while trying to engage the converter housing instead just spins away "metal to metal" and chews up the inside of the converter.

"GAME OVER"

If the tranny will hold "lockup" while it is relatively cool but as things reach full temperature starts to bump or slip and then fails to hold at all, you are seeing clutch failure.

(Cool oil is thicker and the pressures are slightly higher affording a little more holding power on a failing clutch)

The practice of wiring up or otherwise making the TCC work in the lower gears is a bad choice on one of these transmissions. The clutch was never meant to handle this type of useage and will fail fairly quickly.

Using the TCC for engine braking, although handy, is also a bad idea.
The same issue comes up, the clutch is being asked to do what it was never designed to do.

THE AFTERMARKET tranny boys do offer converters that have much stronger clutches.

Many of the replacement converters for the 4L80 and the large Ford trannies, Dodge too can be ordered with "Multiple disc or HD Kevlar" clutches that can withstand far more abuse than the stock clutch.

Most clutch lining in these things is a "Paper material" that is treated and bonded to the steel clutch plates.

Once soaked in oil it becomes a very good friction agent, up until is slips and then "BURNS" once burnt it turns to carbon and the game is over.

Semi metalic clutch frictions are used in some areas of the transmission depending on the torque load requirments.

The converter in the 700R is very small and when you add the clutch assembly the internal area for the pump, turbine and the stator become even smaller.

The 700R converter as it is stock simply is a very poor excuse and is prone to failure when used in rough service.


Removal of the pan and a peek at whats in the bottom will in most cases reveal if a TCC has failed do to wear.

A worn out TCC will leave lots of metal flakes as well as ground up clutch lining (Dark flakey stuff) in the bottom of the pan.


Moral of the story, the 700R converter is best used as it was designed and allowed to only engage above 45 MPH and then only in 4th gear.

Yes yes yes, I know, many of the 700's will engage lockup at or around 30 MPH in town and loaf along, chug chug chug.

Not a good idea at all.

The later 700R, The 4L60E has all this crap handled. The clutch comes in after 45 MPH (In most cases) and will not allow for the low speed use of the TCC.

If you want to use the TCC for low speed and or compression braking, spend the $$$$$$$$$$$$$$$$$$$$$$$$$ and get a converter built that can handle that task.

OH Plan on some serious Bucks too $$$$$$$$$$$.

Another thing you need to be aware of.

The input shaft in the 700R is a piece of swiss cheese, it has more holes and passages that a coal mine in Virginia does.

This effectively weakens the little critter a BUNCH (late 700 stuff "after 86" are BETTER)
Now this said, there is another sand trap in these things too.

The input clutch drum is made of ALUMINUM and the input shaft is just pressed into the splines in the drum.

Using a low engagement TCC allows a lot more forces to be placed on the aluminum splines (Low speed power pulses and vibrations)

The splines loosen over time and then shear off. "game over"

A hardened steel ring is available to press over the splined hub in the drum. This device stops the hub from expanding under abuse and will "HELP" keep things alive in there.

All in all, the 700R is a light duty gear box. Sure it can handle a fair amount of work but you had better plan on spending some serious $$$$$$$$$$$ if you want to make the thing reliable.

IMHO the 700R is not nearly as strong as the TH350 is in stock form.
A TH350 with a simple shift kit can stand some seriouis abuse and live.

Now the venerable old TH400 is a TANK. A shift kit and cooler is all it takes for one of these in stock form to handle some real serious thrashing.

Back to your 700R TCC issues.

Yank the pan and see whats lurking in the bottom. If its full of lots of crap, the clutch is likely gone on to greener pastures.

If clean then check the supply of power (12V) to the wires feeding the clutch control solenoid.

At road speed there should be power to the solenoid.

There are at least 16 yesssss sixteen different wiring types for the 700R TCC setup.

If the rig is stock and has not been messed with then it may be an electronics issue.

Now if the clutch will hold when the tranny is "cool" then the issue is the clutch as I mentioned before.

Hope this tutorial on the 700 helps some.


MGW

 

[turbovanman]

Thanks for the tutuorial, I do/did build tranny's so I am well versed in all that stuff, :thumbsup:

As for my issue, its fixed. There is not much info on how this work so this is how it works.

There is the TPS switch, and a 4-3 pulse switch inside the trans, that's it.

The manual want's you check continuity between pink and yellow then you use a certain thickness gauge and set it at WOT, using this X gauge, you set the TPS, then you insert another thicker gauge and check for no continuity.

This is how I did it after messing around and figuring it out.

Hook up Ohm meter, look for an continuity, then simply rotate the tps until a certain point, I put it at 3/4, then moved the throttle looking for the circuit to become "open", this is the point the OD will unlock, so you can taylor WHEN you want your LU to kick out. I set mine at aprox 1/2 throttle as my LU comes on in 3rd and 4th, which can really lug the engine down. I am going to hook up a toggle switch to the TCC wire and turn it off around town and when going up hills, you use way less throttle when I had not working.

 

[randomid25]

Summary of Missy's post above ^^^^

Stock 700R4 = JUNK!

I'm getting rid of mine ASAP.

 

[Missy Good Wench]

Random

Wrong summary my friend. A 700R4 from the 87 and up years with the proper work done on it is a fine "Little tranny"

After installing all the aftermarket upgrades in one of these, they are fine for most applications that are not beeing yarded around by a monster thats laying out huge gobs of power and torque.

I can build one that will hold a fairly well endowed 6.5 TD and do it just fine.

Just be prepared to spend some serious $$$$$$$$$$$$$$$$$$$$$$. If you do the bench work yourself and buy the parts right you can build a Killer 700R4 for under $2000

If you have to pay someone to do it all including retail on parts you had better have a FAT wallet.

The last one I did cost me about $1500 and it kicked ass.

The stock 700R4 is a sorry lot. Nuff said.

The stock 4L80 is Ok but can stand some lovin for sure.

A TH 400 with nothing more than a good shift kit will take almost anything.

The TH 350 with a kit can hold a well built 454 and go wheelin and do fine.

As is with any auto tranny, you just gotta use your head. You get stupid with the thing and your gonna break something.


The deal with the 700R is that you need to build it to do what you are going to do with it.

A stock 1500 Burb with a 6.2 can do fine with a near stock (later model) 700R with nothing more than a tansgo shift kit.

NOW if ya gonna go a wheelin the thing out in the boonies and pound the ever lovin crap outta the little creature yo need to wratchet up the antee a tad more and build one with all the upgrades.

Even the latest Allison will come apart if you use it hard enough.

There is just nothing that can take the rigors of off road use without eventually going south.

Its all about what your gonna use it for.

Build to to do what you need and your set.


Missy

 

[randomid25]

It's just cheaper and preferable for me to run the sm465. I doubt i'm gonna break that thing or the 205 case even with the 6.2 turbo w/ hot pump and some other goodies. See my previous post for an edit in the spirit of accuracy.

 

[just a number]

I hate to say it but you can destroy the sm465. just get it warm enough. I managed to melt the 1st gear bushing in my first one.

 

[randomid25]

And what were you doing to get it that hot?

 

[turbovanman]

All auto's have weak points, as do manuals.

Nothing wrong with a built 700r4, especially if you start with a 89/90+ trans.

If you want, put a 200r4 in, they have a better gear spread and can also be built right.

350/400's are nice but for highway use, annoying, :sad:

Update, working fine but the TCC simply comes on too early, going to put a switch in and then I can turn it off for towing and in town use.

 

[turbovanman]

Put the switch in, around town, so much better, then I just turn it on when on a long flat road or on the highway, makes towing nicer too.