Installed 700R4 - Hook Up Lockup or not?
 

Good Morning Guys,

We just completed the 700R4 trans install into our 69 C10 and we are amazed what a difference a 4th gear makes. We had a Bullet-Proof Turbo 400 that we loved from Red Light to Red Light, but the highway driving was killing us.

With our Turbo 400, we were running 70 MPH @ 4,200 RPM and couldn't hear each other talk in the cab. Now, with our 700R4, we are running 70 MPH @ 2,200 RPM and loving every minute of it. Cruise Inn's and Car Shows in different cities are now an option for us.

My Question to all of you is about the lockup in the 700R4. I currently do not have it installed and the trans is running perfect with shift points at 2,000 RPM. Will I hurt the transmission if I do not install the toggle switch to the Lockup in 4th gear? Or, based on your experiences, should I install the toggle switch and install the lockup? I now have one weekend of experience with our 700R4 and I just don't want to do (or not do) anything STUPID and accidently trash this transmission because I just didn't know...

Any information from those of you with 700R4 experience would be GREATLY appreciated. I am planning on driving the truck over to my son's College Campus this weekend so he can see the difference in the transmission.

Thank You ALL for Any Information,
Kirk & Christopher Edmunds - Father and Son Project
1969 C10 Stepside with BB 396

Re: Installed 700R4 - Hook Up Lockup or not?
 

I would use this kit, its inexpensive, works great, and you dont have to use a toggle switch, it does it automatic all by itself!

http://www.jegs.com/i/TCI/890/376600...Fcef4AodnlAALQ

Re: Installed 700R4 - Hook Up Lockup or not?
 

With an overdrive ratio of .7:1 your rpm numbers don't make sense, but I digress.

Yes, especially with a BB, I would hook up the lockup converter. You'll reduce the rpms by another couple hundred and keep from overheating the fluid.

Re: Installed 700R4 - Hook Up Lockup or not?
 

They mention in the write-up's about a manual override but no details on it anywhere. You may not have to use it but it says in a reply to one of the questions that it uses a 12 volt "switched" power source. I would say that would be the manual override.


Here is the reply to the question below the video at the youtube website:

"Our 376600 lockup kit doesn’t need an ECU. It’s a standalone kit that provides torque converter lockup with a switched 12V source. The stock ECU normally regulates this on factory vehicles."

Why would they need the switch if it is automatic, unless they have had problems with it not unlocking at times.... Just sayin'

LockDoc

Re: Installed 700R4 - Hook Up Lockup or not?
 

I would not use this kit. I installed their kit in my truck years ago (only difference is the vacuum switch), however, their kit still does not address panic stops. I had to lock 'em down to keep from hitting a moron that pulled out in front of me. The converter didn't unlock and stalled the engine... NOT GOOD with power disc brakes. Luckily I missed the moron and slowly coasted to the side of the road.

This is the kit I've been running since 2006. It has a brake switch so when you hit the brakes the TC unlocks. Unfortunately, you will need to drop the pan again:

http://www.bowtieoverdrives.com/cata...php?ITEMID=332

Yes, install the lockup. When the TC is locked it reduces slippage, which reduces heat, which reduces wear.

Re: Installed 700R4 - Hook Up Lockup or not?
 

type this (torque converter lockup) in the rectangular box by your PM messages at the top of the page. Check the 67 to 72 dot and click on Google. That will give you about a week's worth of reading on the subject.

Re: Installed 700R4 - Hook Up Lockup or not?
 

I agree, when I copied the link I thought it had the brake switch like the Bow Tie Overdrive kit. My apologies. Definitely hook up the lock up, you'll be much happier in the end and dropping the pan is easy enough. Also, install a nice aftermarket trans cooler if you haven't already. The one in the radiator is not very efficient.

Re: Installed 700R4 - Hook Up Lockup or not?
 

Definately hood up the lock up converter....unless you want to put in another trans very soon.
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Re: Installed 700R4 - Hook Up Lockup or not?
 

Yes buy a kit doesn't matter which one that's your choice.

The kits all basically work the same by sending 12 volts to lock the converter up over 45MPH and unlock under 45 MPH. Mine is the B&M shifter kit.
Mine has been in the truck since installed back in early 90's with no problems. I have the toggle switch kit.;):chevy:

Re: Installed 700R4 - Hook Up Lockup or not?
 

I have the TCI lockup kit in both of my trucks, even beating the H--- out of the S10 it works fine. I notice the lockup more with the 64 as I'm running 3:73's and you can feel it when it goes into OD.

Re: Installed 700R4 - Hook Up Lockup or not?
 

I've got a 700r4 with a 2600 stall tq converter and a 3.73 rear end. 70mph at 2200 rpm, when I floor it to pass it downshifts perfect into 3rd and off I go. If I'm real easy on the gas it'll go into OD at 35mph. Remember how important your tv cable is though. The lockup is just a pigtail that plugs in, Run a positive and negative and you're good to go.
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Re: Installed 700R4 - Hook Up Lockup or not?
 

i like the lock up too you can get a late 80's square body brake light switch to get it to un-lock but I put a toggle switch also for the stop and go traffic

Re: Installed 700R4 - Hook Up Lockup or not?
 

TCI has a vacuum switch (runs on same vac as th400 modulator). This sends signal to 4th gear lock up solenoid. It also unlocks based on vac. It works on negative side of circuit by grounding or un-grounding. You still need a cruise control brake release switch so converter will on lock when you run up on traffic and hit the brakes. No toggle switches involved.
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Re: Installed 700R4 - Hook Up Lockup or not?
 

i say you defitnetly get the lock up kit. im in the process of swapping out my th350 for a 700 and i bought the painless wiring kit.. comes with everything you need and you wont need to use a toggle switch to lock it up.. basically works how its intended from factory..

Re: Installed 700R4 - Hook Up Lockup or not?
 

Yes, use the lockup. But you don't need a lockup kit. If you run a simple 12v (key on, engine running) source through the 4th gear pressure switch on the trans valve body, the TC will ONLY lock up in overdrive. Once you're at speed and the trans shifts into OD, then the TC will lock up. As you slow down and the trans downshifts out of OD the TC will unlock. No issue with stalling out at a light.

When I first set up mine, I did the whole kit that incorporated the brake light switch and the vacuum switch. It was all extra wiring that added no functional value to the lockup operation, so I simplified it to what I described above.

Re: Installed 700R4 - Hook Up Lockup or not?
 

I would install it. I would use both the external vacuum and brake switches and internal 4th gear switch so that it only locks if you are 1) in 4th gear 2) no on the brakes and 3) have intake vacuum (not accelerating). If any of these conditions is not met it unlocks. Simple.

Re: Installed 700R4 - Hook Up Lockup or not?
 

I have wondered how this is dont for quite some time. Does it lock up as soon as it shifts into OD?

Re: Installed 700R4 - Hook Up Lockup or not?
 

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Re: Installed 700R4 - Hook Up Lockup or not?
 

doesnt having a toggle switch defeat the purpose of an "automatic" transmission? Before I was a car person I had 2 70's blazers with 700r4s with no ECM and I didnt toggle any switches and when I panic braked the truck didnt shut off... Of course I have no idea how they were hooked up, wish I had cared back then... I dont see why the toggle switch is even an option to be mentioned. seems unsafe for a street vehicle.

Re: Installed 700R4 - Hook Up Lockup or not?
 

I would say it depends on what type of T/C you have. If you have a stock one, then yes, you will need to get a lockup kit. If you have something non-stock, then you will have to look at the specs of the T/C to see if it needs to be locked up or not. You can get a T/C in either lockup or non-lockup versions for a 700R4.

When I installed my 700R4, this is what I did. However, these are getting harder and harder to find.
http://i494.photobucket.com/albums/r...00r4lockup.jpg

Re: Installed 700R4 - Hook Up Lockup or not?
 

Yes, it locks up as soon as it goes into OD and stays that way until the trans downshifts from OD to 3rd. I now have mine wired exactly as the article posted by "nightmare" describes.

Re: Installed 700R4 - Hook Up Lockup or not?
 

The toggle switch I have is to use the lock up are not. If I'm towing my 18' trailer with the truck I want lock it in. My 71 works great even when backing up if the toggle switch is left on. It doesn't effect the trans. This setup was installed when I bought the 700-R4. Once the speed drops off below 45MPH it unlocks weather the toggle switch is turned off are not. Panic stops are not a problem either.;):chevy:

No it doesn't defeat the purpose! First off the 700-R4 has to have some kind of signal to tell it to lock up. How it's done is up to the owner.
Why do u think a toggle switch is unsafe is beyond me though.

Re: Installed 700R4 - Hook Up Lockup or not?
 

Thanks, that's what I thought it would do, just wanted to be sure.

Re: Installed 700R4 - Hook Up Lockup or not?
 

I would I have a b&m works great you control when it kicks in it will drop your rpm even more

Re: Installed 700R4 - Hook Up Lockup or not?
 

I have a 86 700r4 that seems to have a bad 4th since it doesn't ever shift from 3rd to 4th. I think the last guy might have messed it up some how. I read that 4th can go after a rebuild or if someone doesn't have their TV cable right.

If I run the 700r4 in "D" instead of "OD", will it let me get by without having the lockup cable hooked up? I have heard that 85 and up will not burn up, if you run without lock up, but I wish I knew for sure. I like it how it is and it drives like a turbo 350, but I am wondering about excessive heat and wonder if that excessive heat is only when TC spins in 4th? My solenoid only clicked once and is probably bad, which is another reason im fine with no 4th.