I had my crossover from TBI to carbed done professionally, and when it blew jegs and the shop that did it said it was because there was no computer controlling my shifting and that was what the tcc kit was for

 

Thats sounds like a shop giving you bs to get out of a warranty claim. If they did a 'pro' job, tcc control should have been part of that.

That aside, the ecm does not control shifting anyway, it's fully hydraulic. Also you'd have to drive long distances for a long time in OD with no lockup for it to cause any damage - did you?

 

Sounds like you had no output from the vss, which both the speedo needs to read and the ecm needs to decide when to lock the tcc. Fixing it re-activated the lock-up, which feels as you describe.

 

+1

The TC doesn't control shifting in any way,... shifting is controlled by fluid pressure and that's regulated by the Kick-down cable and the governor. It's MUCH more probable that a improperly adjusted kick-down cable was responsible for your tranny failiure.

 

So what can us carb guys do then? I'm doing a 350 carbed swap later this year and I plan on picking up an 87-92 700r4 and want to have my tc lockup eventually. I'm deleting the computer with my swap so do I have to get a wording kit for the lockup or can I wore it to a toggle switch?

 

I haven't read the whole thread but I currently do not have a TC Lockup on my Bowtie Overdrive since I've removed the computer.

On a 100 degree day at 45 mph driving around town with a stand alone transmission cooler the tranny never got above 140 degrees.

This is only temporary but for the 10 miles I drove I had zero problems with the temperature.

 

Here's a factory Vaccum TCC:



This kind of vacuum system was used on most export thirdgens that were shipped without an ECM. The same type of unit can be found in other GM trucks vans in the early-to-middle eighties.

You can also get a similar vaccum operated system from the aftermarket, get an electricly switched version, or wire it yourself to a toggle for manual operation.

 

it's easy to wire it up, no need for a kit- use the wiring that's already in the car and just do a little reconfiguring.. the solenoid gets power thru the plug on the back of the brake light switch under the dash, then thru the plug on the case, and then to the TCC solenoid.. this is keyed power and the wire is hot when the key is in the "run" position.

the solenoid is activated by grounding itself thru a switch in the 4th gear pressure circuit in the valve body- similar to how an electric cooling fan is turned on by a temp switch in the intake manifold. if you want, you can also have it ground thru a switch in the 3rd gear pressure circuit and have lockup in 3rd gear, too. you can also put a vacuum switch in the power wire to unlock it when engine vacuum drops for whatever reason (lugging, WFO on the pedal.. whatever). this switch can be found in late 80's Chevy/GMC 1/2 ton trucks with a 700r4 trans.

so break out the test light, drop the pan off the trans, and start figuring out which wires and switches do what.

 

You cannot go wrong listening to Dana at Pro-Built transmission. He responded to this a long time ago way up in the discussion. Follow his advice specifically. Call him if you can. He is one busy man so have your questions ready ahead of time. And for the record 4th is not the same as third. In fact with the TCI or other methods when the converter locks it is like one more gear. You might as well call it a 5 speed.
Next there is no way to hurt the converter without the lock up engaged. As was mentioned above it is small and fragile. It only should be operating under a light torque load. Now forcing it (the converter clutch) to gobble up the slippage on a high stall torque converter with high loads will ruin it. I am sure Dana would agree. If it is your intent to pour the torque to it, it will fry. Don't try to save money here. If you have a high stall converter 2500 and up, it had better have a good clutch if you are going to use lock up and it won't be cheap. Enjoy the high stall and a nice cam and let it lock in 4th only with light loads. I tried all three methods. Factory computer, Trans-GO no electric required 700-LU and the TCI. Dana recommended to me the TCI method with a good Precision converter it works awesome and while testing it proved it. With the hydraulic Trans-Go 700-LU I turned my Bird loose with way over 500 ft. lbs. floored it from a dead stop. The tires started to cook and 2nd gear shift was immediate seconds later with the tires frying and the motor at a solid 7000 rpm the 700-LU locked the clutch (it works off of the trans governor presure) while the tires were smoking and I had it floored. The precision clutch hung on. After several attempts and spring changes out it came. The TCI method is very, very good. I wouldn't consider going back. I get all the torque a good 3500 rpm converter will give me in every gear. If I drop off the throttle and cruse it locks at 10 Hg. Units of mercury. Perfect. I wouldn't do it any other way. I am positive continued use would have broken the best of the converter clutches out there. They are not intended for full power. The double large diameter converter clutch holds up the best.

Bob

 

I got my lockup on a dash mounted switch.On longer drives I hit the switch and watch the RPMs drop

 

That might work fine for now, but forget to turn it off a few times and you'll find the it'll be hard on the clutch. It's much safer to use a vacuum controlled switch in a daily driver setup like others have described on this forum.

I talked to Dana from ProBuilt about that a few years ago and he gave me that advice. A properly adjusted vacuum switch type will unlock under throttle and if done correctly will unlock still when the brake is used. That makes those panic emergency stops that much safer. If a motor bogs and happens to die that means no power brakes or power steering.

My thread is properly around here somewhere still and I detailed how I made that switch setup with an indicator light showing lockup for under $20 using all new parts (hoses, connectors, switch, and indicator light).

 

Regardless of what TCC setup you are using ( elec , man , vac )
you should always wire through the factory brake switch so the convertor unlocks when brakes applied

Just as easy to install the 4th gear switch in the valve body so convertor locks up anytime the trans is in 4th
No need for any other switches or wiring, just 12V from the factory TCC brake switch to the trans
which you already have in place as part of the stock TCC wiring
Drop the pan , install the switch ,swap a couple of wires around in the trans and refit the pan ; drive off

 

No. Some if not all (not 100 percent sure after all the valvebody changes) GM 700R4 transmissions required lockup of the converter. but there is a correction/ mod kit out there by TRANSGO that makes it possible to run a non-lockup converter on the 700r4 pump. 700LU is the part number


.]

 

I don't think lockup always in 4th would be good for my application. Dana setup my 700-r4 for WOT 4th upshift and no downshift out at WOT. Maybe if I had a multipack clutch upgrade like the vigilante converter with upgraded options, but I'm running a cheaper converter.

 

I have run my 700r4 at various Temps
Cold 20 F - 140 F in winter
Hot 80 F - 195 F in summer
Ave Temp on light drives 150 F
I have a non-locking TC 1800 Stall
A trany cooler looped into trany lines going into the Rad
4:10 16r70/235
I can lay rubber no problem
However, the tranny does get hot very quickly depending how heavy a foot you have.

 

So how would I know if my car has a lock up or not? I'm looking at buying a new torque converter and some pop up as non lock up and others say lock up. Any help?

 

If the car is driveable, put the trans in OD and gradually accelerate and note the 1-2, 2-3 and 3-4 (OD) shifts.

The converter should lock up either in 3rd or 4th (OD). The lock up in OD should occur around 45MPH. It should feel like a soft, fourth bump.

 

Since this old thread got bumped , I figure this is the perfect time for a moderator to do some moderating and eliminate this BS personal attack against a contributing member of TGO ? When you DO finally eliminate the BS personal attack post , fell free to remove this post as well .......

 

From what I have read, to me nothing in this thread warrants any moderation at this time, no personal attacks against anybody were made, an opinion was given and the proper response by the moderator you quoted was given in my opinion. This day in age criticism is to be expected and as long as no name calling, threats were given etc. everything will stay as is. You can further PM me if you feel otherwise. Thanks!!

 

Agreed.

 

No need of PM , I just thought it downright rude of someone to say that Dana's advice is dishonest by way of giving out false information to sell parts . That is what was said , it is a "cheap shot" , and your own rules & moderation system call out "rude" posts as being not acceptable .

I just figured you'd want to remove an insult to one of our most helpful members ..... Whatever . Not my circus , not my monkeys .

 

have had my car for 25 years. when I got it back from lingenfelters. it was a none lock up with a 3000 stall and 4.11 gears.and a trans cooler after the rad.
was never over 130 deg also had a guage . drag racing hot loop never over 150deg.(making 3 or 4 back to back runs) city drive never over 130deg..2 fans both kick on at the same time also..no AC..

 

I am waiting until tomorrow when I order parts to talk with Dana about the TCC lock up. I have been running my car with the lock up not working for a while now. I have 3/8 cooler lines and dual external coolers. I have never seen the trans fluid get more than warm.

I can't find the information today, but I seem to remember reading something, either from Transgo or maybe it was an ATSG tech bulletin about lube fluid flow through the converter and cooler with the TCC unlocked. It seemed to me that the TCC valve train had been updated in later model years to improve flow. Something about the size of the hole that is in the TCC valve retainer in the pump. It may have been Dana that told me this too. I think he said it could be improved further by increasing the size of the hole. I'll ask him about this tomorrow. The later style pressure regulator valve with the flats cut into it, or the lube flow increase mod to the early style valve, grinding the second land down, increases cooler and lube flow in all modes of operation.

I will work on getting the TCC lock up working again, even though I hardly ever use it. With my current setup, it's pointless anywhere but 70mph on the freeway. With my next motor and more low end torque, the TCC may be of more use.

I have ACCEL DFI so the VSS and such are a non issue. It's too bad that ACCEL never got the full function of the ECM TCC control working on the gen 6. It would have included load and TPS values in the control strategy.

As it is, the TCC relay, an optional add on to the DFI system, is on whenever the brake is released. From there, the 4th gear pressure switch is the only thing operating the circuit and handles the full load of the TCC solenoid. The switch is bound to have a high failure rate in this design.

I plan to use the two unused circuits of the TCC harness to route the pressure switch signal out to the control circuit of the relay so that the relay will directly operate the lock up solenoid from the 4th switch signal. This will increase the life of the switch by removing the solenoid load from it. Like installing a headlamp relay. The better OE designs routed the press switch signals to the ECM and the ECM controlled lock up. My redesign will be better yet by using a relay to control the load.

If I'm not too lazy about it, I'll post up a diagram of my design for others to follow.

 

Something I've become aware of that is related to this discussion is the TCC lube feed restriction in the pump. It restricts lube fluid to the converter and on to the cooler and gear train through an .080 orifice when the converter clutch is engaged. The late style or modified pressure regulator valve, that allows lube flow to the converter, through the cooler and onto the gear train whenever the engine is running, is of course a must have. That alone however doesn't help the restriction when the TCC is locked.

The best advice I've heard is to open the orifice up to .110" for increased cooler and lube flow, without reducing TCC apply pressure. To access the orifice, you will need to separate the pump halves.

 

I wanted to revise what I said in my earlier post about not running the TCC solenoid directly through the pressure switches. I had said I was thinking of routing solenoid power trough the TCC relay in my ACCEL DFI system to reduce load on the control circuit. I wasn't sure then just what kind of current the TCC solenoid would draw. To find out, I just ohm tested an old TCC solenoid I have on hand. It tests at 24 ohms resistance. At 12 volts, this solenoid would draw .5 amps. A relay coil draws .5 amps. Therefore, there would be no benefit to using a relay to control the TCC solenoid.

 

My lockup quit working almost 5 yrs ago, still haven't spent the time to figure out what or why it died. Was working fine then.. nothing. may be as simple as the solenoid.
Trans has never been more than warm even on long highway trips.

 

My lockup is useless at less than 65 mph. All it does is lug the engine below that. It will be better once I have more cubes and better low end torque. The 355 with huge cam doesn't like the low rev load. I've never had the trans get more than warm cruising with no TCC lockup and the 3,500 stall converter.

I'm thinking mine may have stopped working because I left something disconnected. Honestly, I have to go over it to remember how I even wired it up. I used the fog lamp switch as an on/off override to prevent TCC lockup in 4th gear and the cruise cancel circuit of the stoplight switch to unlock it with the brake applied. How I put it all together, I just can't even say right now. Guess I should have saved the drawing I made then.