scottjkj1
Registered Member
What happens when you run a 700r4 and dont lock up the coverter?. I know it runs a little warm and being its slipping like regular tranny and you dont get as good as gas mileage but will it actually hurt the tranny?
CK5
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700r4
- Thread starter scottjkj1
- Start date
It gets VERY hot and will kill the trans in short order.
scottjkj1
Registered Member
Is it only suppose to lock up in 4th gear?
While this may be true, I have been running a 700R4 behind a 406 SBC in my 88 Camaro with a non-lockup converter for 3 years without any problems. Before that the trans was in my 83 Camaro with the stock converter (lockup), but I wasn't running a computer to control it (the lockup). Also saw no problems with running it this way.
Both of these cars had/have large aftermarket trans coolers in them though.
I don't think it's the running non-lockup that hurts the trans, it's the heat that does it. But the converter is only supposed to lockup at crusing speeds. Not lockup and shift through the gears.
Personaly I wouldn't worry to much about it not locking up. But that's just me, based on my own experiances.
Most of the 700's will lock up in 2nd, 3rd and 4th.
If you buy the kit to eliminate the lock-up feature then the trans won't get hot and burn up. I don't know what the kit consists of though.
If you buy the kit to eliminate the lock-up feature then the trans won't get hot and burn up. I don't know what the kit consists of though.
scottjkj1
Registered Member
The reason I ask is I got a manual switch for the lockup, at highway speeds ill flip the switch and you notice the rpm gauge drop so its locking up. I noticed though that it doesnt lock up on its own. Its was obviously put in aftermarket and is in a 89 suburban. That being I dont think it locks up on its own and has been that way for the 3 years I have had it and it hasnt burnt up yet. I do have a temp gauge on it and it does run a bit warm but I use synthetic fluid and it doesnt get to warm so im guessing its fine. Ill have to do a little research on it and trace out the wires and see if it does have some type of aftermarket lock up controller on it thats not working. If it doesnt does anyone have any recommendations on one. The problem with the switch is I forget to turn it off when I slow down to stop. Of course I realize this pretty quick as it lurches and sounds like its coming apart.
shaun89
1/2 ton status
ive been wondering the samething, im puttin in a manual valve body 700r next week (if my TC gets here) and was wondering what i should do about it...
My '88 came with the 700r4 and had recently been rebuilt when bought at 116K. I noticed that there was no lockup function, but never really thought much about it because there was a large tranny cooler installed. At 138K, the tranny started to die, so I had it rebuilt (but stronger). After being rebuilt, the lockup function now works again. Anyway, the tranny only lasted 25K-35K with no lockup.
scottjkj1
Registered Member
Im going to do some research on this lock up controller http://www.jegs.com/p/B%26M/748070/10002/-1 Anyone had any expierience with it or have any other suggestions. Ive seen some pretty exotic ones out there but Im not wanting to spend 700$-1000$.
If you have a Lock up button, your trans will not lock up on its own.
I am about to install a manual reverse valve body and a lock up button on my 700R4 in the next month. I am doing this for crawlin. With the lock up button, you can crawl down a steep hill in first and 4low, and then hit that lock up button to basically cut the gears in half. Pretty cool huh. With a lock up button, you can also push start your truck like you would a manual.
I am about to install a manual reverse valve body and a lock up button on my 700R4 in the next month. I am doing this for crawlin. With the lock up button, you can crawl down a steep hill in first and 4low, and then hit that lock up button to basically cut the gears in half. Pretty cool huh. With a lock up button, you can also push start your truck like you would a manual.
pauly383
Daddy383
Wow thats expensve . I would rather do what they did in the begining : a vacuum switch for the lockup based on manifold pressure .
Lots of 82-84 K5's , and other early vehicles sitting in yards waiting for you to yank it out way cheaper than 175.00
( my 83's harness made it onto the truggy , with the 83's 700 . I have run the SAME 700r4 since 2001 when I bought the 83 )
You can run any gear but 4th without the lockup. 4th is where you cook it, but this depends on a lot of variables. One big one is the stall speed of the converter. The higher, the hotter. To get lockup in 4th, you only need to connect 1 wire, so I don't see any reason not to do it. This wire should be fed through a brake pedal switch. The 700 has an internal switch to unlock while shifting.
Now with a manual valve body, all of the hydraulic signals could be different, but all you need is a pressure switch on the 4th gear port (assuming the valve body has no 4th pressure switch built in). Run that in series with the brake pedal switch to the solenoid and you're done, right? Maybe the manufacturer of the valve body has to answer that for you, but it seems like they would apply the hydraulic pressure all the time. I don't know if the 4th pressure port would go low fast enough to unlock for the 4-3 shift, so that could be a concern.
Now with a manual valve body, all of the hydraulic signals could be different, but all you need is a pressure switch on the 4th gear port (assuming the valve body has no 4th pressure switch built in). Run that in series with the brake pedal switch to the solenoid and you're done, right? Maybe the manufacturer of the valve body has to answer that for you, but it seems like they would apply the hydraulic pressure all the time. I don't know if the 4th pressure port would go low fast enough to unlock for the 4-3 shift, so that could be a concern.
shaun89
1/2 ton status
ive heard if u just want a "crude" lock-up set-up is you can just run wires to 2 of the 3 connections on the side of the tranny.if u dont care about a brake switch and just plan on using a toggle switch, is this true?
scottjkj1
Registered Member
The lockup button I have, toggles switch, I was under the impression was just a bypass to lock it up if you wanted to, obviously I dont know what I do have and need to do a little wire tracing.....
For those wanting to put in a lockup switch on the cheap, there is an easy way to do it. It involves tapping into the ALDL. The article is for a third gen F-body, but I'm sure the pins are the same in the trucks too.
http://www.thirdgen.org/torqueswitch
http://www.thirdgen.org/torqueswitch
All the GM trucks until TBI use "mechanical" means of locking the converter, and they are pretty easy to install. No reason I can think of not to use one of those setups if you want it to "automatically" lock, especially when a "kit" costs $175. Need to figure out which pin does what on the trans connector, but that should be pretty easy.
Really not a good idea to use the TCC for anything other than IE cruise conditions. It's not a strong setup, and as evidenced by how GM used it, was never intended for high load conditions. I've read of peoples experiences using lockup in 1/4 mile racing, it helped their times in some cases, but it didn't last long.
It's also about heat...without TCC you generate more heat, and the small stock cooler is not nearly up to the task of cooling the additional heat from lack of TCC adequately.
Really not a good idea to use the TCC for anything other than IE cruise conditions. It's not a strong setup, and as evidenced by how GM used it, was never intended for high load conditions. I've read of peoples experiences using lockup in 1/4 mile racing, it helped their times in some cases, but it didn't last long.
It's also about heat...without TCC you generate more heat, and the small stock cooler is not nearly up to the task of cooling the additional heat from lack of TCC adequately.
carpeonnel
1/2 ton status
I know from personal experience if you put a pre-TBI 700 in a TBI Chev the lockup won't work on it's own and you have to change up the wiring. I found this out cuz my local shop took my original 700 out and tried to pull a quickie and stick an 86 700 in. Lock up wouldn't work, blah, blah, blah,....said screw it and now I'm manual 465. Couldn't be happier, now
scottjkj1
Registered Member
The 700r4 I got was suppose to be built to take a lot of torque, other than the heavy clutches he named off a lot of other stuff, I think output shaft, servo and I want to say sun shell but dont quote me. Anyway since I put my 37's on the truck I will more often than not keep it in 3rd gear even on the hiway, unless its pretty flat. I do this because I got 4.11's in it and need to go higher to get back into the power band, it downshifts a lot in 4th in hilly terrain. So my next question, is there a problem locking the converter in 3rd on the highway?
scottjkj1
Registered Member
well I traced out the wires. The purple wire is hot when the key is on, the green wire is not used and the white wire with the black tracer goes to my toggle switch that just sends it to ground when its turned on, obviously completing the circuit. So im thinking this has no auto lockup feature, just a manual switch. Question is when I turn the switch on does it lock up every gear or just 4th. I know if I leave the switch on and slow down to a stop the tranny makes a loud clunking sound.
With the set-up as you described the convertor is locked as long as the switch is on. If you leave the switch on and come to a stop the engine should die (just like stopping with a clutch and not holding the clutch pedal or putting it in neutral.
