73duster

I just want to know if i can run my 700r4 without a functioning lockup? Will it damage the tranny or will it only affect fuel mileage? I know i should run it, i just want to know if it will damage the tranny without it? Please no" why would you want to?", i'm just looking to know if it will work ok without the lock up. thanks

Apeiron

It will work, but the transmission will run hotter and it will shorten the life of the fluid or the transmission.

Ilike2stroke383

yes it will work for a few miles. maybe just enough to the local junkyard. if your lucky it will make it all the way there and you can swap another tranny in the lot!

Apeiron

It'll work for a lot more than just a few miles.

larrybldr@gmail

no, it will not hurt your tranny!!! all the trannys thru the 70's (ex. Turbo 350) were non lock-ups... my son just had a 67 chev p/up with a 700r/4 behind a BBlk with a non-locking conv.. no problem.. Say later to you ol junk yard..

Apeiron

All the trannys through the 70s were also three speeds without overdrive, critical difference.

sumnerslayer

iTrader: (1)

I currently have a 700r in my car, have put 12,000 miles on it without the lock-up hooked up, never had a problem and it sure beats the hell outta the th350 i had, hated running 3000 rpms at 60mph, now its crusing at 1900rpms without the lock-up engaged, i wouldn't worry about it

ls six

Some people on this thread seem to lack real knowledge about how a trans works, yes without lockup theres a chance the trans may run slightly hotter on highway cruises.

But no it will absolutely not harm the trans, since the lockup only works at very low loads the aditional heat is still much less than it would experience during "spirited driving" or even driving around town.

In daily driving the clutch may only be engaged ten percent of the time, especialy given the way 3rd gens are typicaly driven

areonic1

Ok, Im not going to tell you what Ive heard or what I THINK i know. Im just going to tell you what happen to me.

Car was running fine, had everything checked out after installing TTs. Removed the lockup, drove about 8 miles literaly, let the car sit for a week, tranny and converters now useless. You can rev the car all you want, and it crawls at 5mph at best.

So Im not gonna bother relooking here for an argument, just general comment based on what happen to me a few weeks ago, and it was do from not having a lock up. Then again, Im sure someone here will say the tranny shop didnt know what they were talking about.

Anyway, good luck

ls six

TT's as in twin turbos?

And yes your trans shop had no idea what they were talking about, in eight miles a converter in perfect condition may not lockup at all.

Look into the function of a lockup clutch and you'll see why.

cusz28

I had a problem with a 4l60e with the lockup circuit not working, and i called a tranny shop about it. they said it will make the trans run hotter and will block a fluid passage to the rear bearings. not sure if he was right, but my truck went from chicago to greenbay and back with no problem.

westman

OK, I've been out of the game for a while, what exactly does the lock up do???

Apeiron

Eliminates slippage in the torque converter while cruising.

skirkland1980

iTrader: (2)

here is my experience with no lock-up. i drove 70 miles to the nearest drag strip. when i got there the tranny fliud was 135 degrees F. made an 1/8 mile pass, then the fluid was 145 degrees.

Jammin'Trey

Kiss 4th gear away haha.... I had no lockup for about 3 miles... Without lockup 4th gear is the same as 3rd

robertfrank

iTrader: (27)

I've been running without my lockup for about 3 years with no issue. When i get the trans rebuilt i'm just going to hook it up to a switch for "long distance" driving. I'll turn it off for around town and racing.

Apeiron

Umm... no

vortec350s10

I have "heard" that a certain oil passage is only open when it's locked. Like most of us said, you're not going to hurt it very much if at all. But if it's got the original wiring in the trans already and you don't have a 700r4 "non lockup" converter, hooking it up to a toggle is as simple as hooking up a pair of foglights. You don't need one of those hundred something dollar lock up wiring kits. I'll be the one to bring up the "why would you want to?" And why would anyone make the comment that 4th gear unlocked is the same as third? Even my mom knows that.

hellz_wings

iTrader: (2)

I had the speedometer cable unhooked for quite some time (2 months) and drove a couple hundred miles without lock up on my newly rebuilt tranny and TQ converter! I drove on the highway several times as well, usually revving at up to 3000 RPMs constantly for about 30 minutes straight. Have I damaged my tranny/TQ converter? It has a very good b+m transmission cooler (the best one) and it has always been filled up with fluid..

Now that I got the correct gears installed, my speedometer works and the tranny locks up like it's supposed to and it's a billion times better on the highway! Can't beleive it!

camaronewbie

Here's my take:

I agree that without the lockup at extended highway speeds the transmission is going to be hotter, and thus causing the possibility for a faster wear of the internals.

It will most definitely decrease your gas mileage.

Converter issue I would think would be very little if any - more time is generally spent non-highway driving rather than highway driving for most folks. And although in stock form the converter can lock at as little as 35-40mph, it's always locking and unlocking with in-town driving.

There does not appear to be any SES codes for malfunctioning lockup, and the ECM would know if there were an ECM issue with the converter locking or not, since the ECM controls the lockup function. Granted, if the wires from ECM to the tranny, or the internal wires, or any mechanical issue arose that caused the lockup to malfunction - the ECM would not "know" of these issues. But I'd think if it was a very critical issue there'd be some diagnosis and SES coding ffrom the ECM for a non-locking converter. Most folks have a hard time telling even if and when it locks, so GM was not relying on customer complaint with a malfunctioning converter lockup scenerio either.

So, my best guess is that, although it could potentially cause premature wear from warmer op temps, I don't think there's any major short-term ill effect from not having it lock. BUT - I'm NOT a trans expert, and I don't have new tranny cash on hand either, so I make no promises to anyone!

Pro Built Automatics

The amount of slip that will happen when not using lockup will depend on the rear end gear ratio, which torque converter you are using, and how you drive (the intent of the vehicle). The amount of heat that will be produced from not locking up the torque converter clutch, will be affected by the same criteria as above, and the same for the amount of gas mileage loss. If you want to use a non-lockup torque converter, then you must remove the checkball capsule at the front of the input shaft, install the non-lockup valve in the front pump that re-routes the fluid to the torque converter in the opposite direction. Each situation is different. If you have the lockup available, "do not" disconnect this on purpose, as there are no "gains" from doing this. For many years (from 1994 to the early 2000's) I built many non-lockup units very successfully, using Continental 10" non-lockup torque converters, with stalls from 2,400 rpm - 3,000 rpm with no problems with heat, and I used modified 11" low stall non-lockup torque converters for applications where people did not want the lockup, but with a slight loss of gas mileage. There are still a few of my units out there with this setup.

Doom86

My experience with driving with out the lockup working isn't as good as some of yours. My lockup stopped functioning because of a faulty CTS pigtail and I was driving 40 miles to work and 40 miles home every work day and it burned up the transmission. It started slipping a bit for a week or so. The first thing that went was 3rd gear, I was only like 10 minutes from home so I drove home in second with it slipping the whole time. It made it home and wouldn't move another foot after I stopped.

This happened after I fixed the CTS pigtail and got the converter locking up again, maybe like a week or so after.

TUCK1975

iTrader: (1)

just wondering im taking my 305 tbi out of my 92 firebird vert and putting a 355 carb in my car will this change the lock in my tranny or will it work the same as before was also wondering if my cruise control will still work with the carb setup or not any info on this will be very appreciated im new to this kinda stuff and if i have to wire mine up to make it lock after the switch can you leave a link to a diagram or something like that thanks

mikeirocz1

iTrader: (1)

If you have a lockup converter and dont use the lockup on the tranny will it mess up the converter?

camaronewbie

mike: won't mess up the converter any I wouldn't think

tuck: You will need a method to lock the converter, most buy a lockup kit that gets installed into the tranny. cruise - I'm sure it can be made to work, but I haven't personally done it - cc has it's own seperate control module that is located just above the ECM in pass side footwell - I assume it gets it's speed info from the VSS, but under the hood all there is is cable from the TBI to the vacuum actuator.

camarorsssss

iTrader: (2)

I am not a tranny expert by any means, but I ran a non lockup 2800-3000 stall converter on my 700r4 for about 4 years, although i only put a few thousand miles on it, i never had a problem and my tranny is fine. I went back to a lower stall with a lock up but the non lockup did not cause any problems and the tranny still shifts great through all the gears.

camaronewbie

I'm no expert either - all I know about trannies is what I read here.

I wonder if, for whatever technical reason, there is some difference in how hot the tranny will get if running a non-locking converter vs. a locking converter that's not getting locked?

In the later years (like after 1987 maybe?), GM installed a temp sensor within the 700R4/4L60 transmissions that would lock the converter based on heat as well, which as I understand it, locked the converter regardless of ECM input (would override the ECM).

sharkbait

These guys know a little about transmissions. Info below taken from their site.

http://www.transmissioncenter.net/700r4.htm

If you have a 1982-83-84 car or truck never drive it with the wires on the side of the transmission unplugged. This will overheat the transmission on a long trip. On a 1985 or later it is O K to have the wires unplugged, because of a design change made in late 1984. The only part of this transmission that is electronic is the torque converter lockup. You will still have all four speeds with the wires unplugged.......................

If you have a 1982, 1983 or early 1984 transmission (27 spline input shaft) it can be replaced by a 1987 up transmission for a better feel. The wires don’t have to be hooked up on a 1985 up transmission. This works well on the early S-10 Blazer, because when they get old it will rattle when the torque converter locks up. On 1982, 1983 and early 1984 transmissions the transmission will burn up if the torque converter doesn't lock-up.

j dezzy

iTrader: (12)

Ran the 700r4 in my 87 ta for 3 years with no lock up. Didnt have a single problem, and it was my daily driver.

1982Z28Camaro

iTrader: (2)

This is not my thread but it has helped me out a lot, I was planning on putting a newer 700r4 tranny in mine and was wondering the same thing.

ryn28

iTrader: (1)

I think that's pretty much the answer right there. There's a right way to do it and if done that way it won't do any damage.

I had my trans built by a local race trans shop here on LI, Select Transmissions http://www.selecttransmissions.com/ , and they gave me the option of a 12" lockup or 10" non lockup. I had them build me the 10" non-lockup converter which they knew would be used more on the street then the strip. Knowing more heat would be generated without the lockup and the smaller converter I also had them install a higher capacity trans pan and trans cooler as well. I have had absolutely no issues with the trans since this build well over 7 years ago. I should mention the car is not a DD but I still think it proves the point.

ls six

You have to take advice given by any vendor with a grain of salt, this man sells parts for transmissions. Now is it hard to believe that someone who makes a living selling transmission parts may just lean toward telling you you NEED these parts?

Consider that the ECU disconnects the lockup clutch under any significant load, load creats heat especialy when the converter is slipping. How would the trans over heat while running 20-50 drgrees below the temps it reaches under load?

In other words the only time the converter would ever be locked is when the trans is under low load and running cool. If there was enough load to over heat the trans the converter wouldnt be locked anyway.

vortec350s10

I don't see any reason to not run a lock up converter for a car that sees at least some street driving. The price difference is not that much between the two and even if you don't choose to lock it on a regular basis it is there for you when cruising on long trips.

With the factory wiring in the trans, it is easy to wire in a toggle switch to enable lock up when running without an ecm. Now I'm going off memory from 2 years ago, but if I recall the tan/black wire which can be found at the ecm and aldl connector (under dash) is the ground wire for the tcc solenoid and the red is the 12V+ wire to it. The green wire is an output wire which informs the ecm that the trans is in 4th gear (OD). I forget if it is N.O. or N.C. but I believe it is connected to ground and this switch is internal to the transmission. The red wire (12V+) is ran through a N.C. (normally closed) switch on the brake pedal itself along side the N.O. switch for the brake lights. Now some tcc solenoids are only single wire units which are self grounded and rely on 12V+ to be energized. I hope this helps someone out there, in my opinion the lock up "wiring kits" are a waste of money if you simply desire setting it up to be manually operated. You got to keep in mind that the way it is controlled by the ecm greatly limits the amount of torque that is applied to the torque converter's clutch since they unlock under all but the slightest throttle positions. Having manual control you have to be careful to not forget when it's locked so you don't wreck the converter since most aren't designed with enough clutch area to be able to withstand heavy throttle or shifts.

Now the better aftermarket converters from Yank, Precision Industries (Vigilante) and some others can be ordered with HD single or multiple disc clutches that will handle full throttle but in my opinion are not worth it in most cases since the benefits are little if any locking under heavy throttle.

I realize this is kind of a "why would you want to" type of response but I'm just throwing out some information that hasn't been said yet in this thread.

Apeiron

Shearing in the fluid during slippage creates heat, and slippage is highest when load is low, which is also when fluid flow through the cooler is lowest as well.

John in RI

iTrader: (167)

I've dealt with the TCC a few times.

Once was with an 84 Trans Am tranny ( Canadian car with NO ECM, originally a factory GM vacuum TCC car ). The tranny was driven without TCC operation for a several thousand miles & several road trips of 2-3 hours drive back/forth - no problems. Driveline was a 305/700R4/3.42. I figured out what "model" and "type" the tranny was by it's VIN and then re-installed a factory ThirdGen Vacuum controlled TCC solenoid. I've skipped TCC installation on many cars but never for longer than on this car. Read EXACTLY how the factory GM system operates here: https://www.thirdgen.org/forums/tran...up-tourqe.html

More recently I'm dealing with it because the 83 Z28 I rebuilt doesn't have the TCC installed ( yet ). Because this 700R4 is one of the first designs it seems as if TCC is more important than with later trannys due to upgrades over the years. I've only driven on this car for a few hundred miles now but it's on my mind to install a TCC switch ASAP.

Many guys here simply realize that their TCC doesn't work and figure it needs to be fixed. Many other get right into the "finer points" of design and variables. The fact of the matter is that TCC operation can be installed/restored in a number of different ways. Some like to buy and be done with it, some want to spend little and turn wrenches. Either side of the fence you stand on the TCC should probably be used if it's available. There's loads of info in here on the topic for DIYS projects and new kits can be bought for as low as $40. ( Because no one WANTS to throw $400 + into parts / labor for a converter job ! )

After reading a Lot of TCC threads over the years there are not too many actual horror stories of personal experience. I've heard a few ( "drove 5 miles and tranny blew up", ect... ) but experience with the MANY ThirdGens I've driven without TCC when it 'should have' been working tells me that not true. (none of the 700R4s I've neglected to install TCC on have ever failed due to TCC non-operation.) Yet; With no benefit to removing it and so many simple, cheap and easy ways to install a switch - why not get it workin' ?!?!

ryn28

iTrader: (1)

That is a good point and well taken. The thing here is there are other companies as well, like Trans-Go that sell kits or parts, for example, they have one for 7004 & 2004R called the Converter Conversion Valve "For installing non-lockup converter. Corrects lube flow through converter"

Maybe disconnecting the 12v lockup control wire is ok if you still have the lockup converter and don't want to use it, which I wouldn't understand, but for installing a true non-lockup converter on a trans that used to have one, it seems you should do more then just disconnect the wire.

There was a reason I was given when I had my trans done which was why I chose the non-lockup converter but I don't remember what it was. Maybe they didn't have the 10" lockup and only the 12". I don't remember. Either way, being this isn't my DD I have no problems but as stated earlier, I do have the deep pan and aux. cooler to control heat.

chas0218

What if you left it in 3rd gear that wouldn't allow the tranny to lock up and allow a significant amount of fluid to travel thru the tranny allowing it to cool? I know a lot of trucks use tow/haul mode and it doesn't allow the tranny to lock up and stay out of 4th gear.

Thanks, Chas

P.S. --> Sorry OP for hi-jacking your thread but thought this pertained.

Apeiron

You could drive in 3rd if you didn't mind giving up the mileage.

Dante93GTZ

iTrader: (5)

All the BS aside (this thread 'stinks'), Lets look at this logically.

Lets say you live in a small town where speed limits are low and traffic lights abound (ie, place I used to live: IDAHO FALLS, IDAHO)...

Now, lets say you leave your house and drop the kids off at school (~3 miles) and then drive the 1.5 miles to the grocery store. Then you leave the grocery store and go to the gas station which is .5 miles away; then you make some other errands totally ~10 miles; all the meanwhile having gone through 10-15 traffic lights. Under normal circumstances, you haven't traveled long enough or fast enough to have even locked up the converter.

Another mention: They sell TCC solenoids at the parts store for MANY automatic transmissions. I've had them go out before; in most cases they will not let the lockup feature disengage but I have seen them not allow the converter to lockup at all. It seems odd that a part so readily available would be so prone to failing if it caused the tranny to become harmed.

The logic is: With your converter not locked, ultimately, it's slipping. While slipping it will create more friction which will cause more heat. Will the extra heat damage anything? If fluid levels are proper; NO. Can it shorten the life of anything? As long as fluid levels are normal and the trans cooling system is fully functioning, I don't see it even being a remote possibility.

Abubaca

iTrader: (3)

Pro Built Automatics has been a contributing member of TGO for a long time, and the advice given is very often NOT to run out and buy new transmission parts, etc. etc. While I understand the logic, it will be a sad day when we stop listening to the experts, and start listening to the guy who's uncle has a guy who's brother said such and such. Due diligence and research is far different from paranoia.

Not trying to flame or start argument, but listening to Pro Built is better advice than NOT listening because they're professional. If Pro Built was a new memeber with very few posts, then I'd agree, but this is not the case.

Rob's 92 gta

I 89 700r4, I have a 10in non-lockup 3600 stall con. in it I had to do small mods. very easy. I had to remove the check ball in the input shaft and also had to put a non-lockup valve in the front of the pump. I still have that trans setup in another car 5 years and many passes later still works well. You will need bigger trans cooler.

DROBECO

o0k now here's my problem. i just swapped in my 700r4 after the stock one went out at 150k i have a 91 rs 305 tbi. my car stalls when i come to astop unless i feather the throttle. i just descovered my tc is always engaged, also i cannot use my speedo cable because stock speed sensor was a gear and the one that come on the replacement 700 is magnetic. so what can i do to prevent or remidy this stalling propblem?

vortec350s10

Well if you CAN come to a stop without it dying, that's one thing to look at it. I'm not a total 700r4 expert but I don't believe hydraulically that the tc can remain locked when the tranny is in first gear. A simple test would be to simply unplug the connector from the trans. It is located on the passenger side, has 3 wires. Unplugging it will cut off power to the tc solenoid. See what happens and go from the there.

DROBECO

you sure its not one the drivers side? up close to the bell housing? its on a 91 rs. i dont know what year the tranny is but anyways yeah i can do that. what should i expect to happen? and yeah i can come to a stop but the car will try to stall unless i shift into N or feather the throttle

sharkbait

If you can feather the throttle with the car in gear at a stop the TC is not locked up. It would be the same as trying to come to a stop in a manual trans car while in gear without depressing the clutch. I would check the IAC. Also, you should be able to swap out parts from your old trans to use your speedo cable again.

vortec350s10

Yeah your right, drivers side. I was a little hammered when I responded. It's that white connector with three wires. If I remember there's a purple, green, and tan/blk. Unplugging it will not allow power to the solenoid for lockup. The green wire is an output from the trans to the ECM from a 4th gear pressure switch in the trans. It tells the computer that the trans its in 4th gear. If your converter is stuck locked, it would shift firmer and feel like a manual transmission when your driving. Meaning the Rpms will not change with throttle position, only road speed. Just unplug that connector and go for a drive. It'll rule that out real quick if it's an electrical problem with the tcc solenoid.

recordrascal

Last year I got an excellent deal on a car because the origional owners (who dearly loved it) had a used trans installed but their mechanic couldn't make it behave. Disgusted and with no more money for the project they put it up for sale. When I bought it the car wouldn't shift properly, would stall at all stops, sometimes even at low parking lot speeds. and ran very rough. All these things began after installation of the used 700r4 trans. The shift problems were as I suspected, lack of knowledge of the Throttle Valve Cable. The rough running and stalling at stops and low speeds took me a couple days to figure out but went away suddenly when I unplugged the speedo connection in the side of the trans. THE ORIGIONAL TRANS HAD THE GEAR DRIVE WHILE THE REPLACEMENT HAD THE MAGNETIC, I unplugged it because I knew it was driving the speedometer crazy but must also have affected the cars computer. It required no extra expense on my part and runs and shifts perfectly (except for lack of cruise and speedo), on our last extended highway trip it clocked 27.5 miles to the gallon at 80 mph. I haven't yet found a way to change over to the old gear drive. The parts from the old trans won't fit the replacement, possibly changing the tail might work but I'm not sure how much disassembly that would require.

sharkbait

http://www.transmissioncenter.net/sp...n_______va.htm

Take a look at the parts available on the above link. I am sure they could provide you with a solution if email them.

hellz_wings

iTrader: (2)

I bought a new drive gear and driven gear and tailshaft housing from this place. WOrks like a charm! Your overdrive won't kick in unless you have the speedometer cable plugged in so make sure to get it working asap as leaving it unplugged will generate more heat in the trans from not locking up. Although some people will say that it won't damage the trans, personally I would not want to take the risk, and you will get it running much better when the speedo is working because the ECM DOES use speedometer readings for certain functions.

Also get a good tranny cooler to preserve the life of the trans. They are cheap, like around 50$.

TheMonster

The reason your trans blew is because you had twin turbo. Not because you didn't have a lockup converter. A 700r4 stock is only good for like 300tq