700 R4 transmission torque converter questions?

---------

x2

 

Two issues
- 700r4 in stock form needs lockup for proper cooling fluid routing, run without lockup and smoke the trans UNLESS you do the mods needed to go no lockup.

- TH350 went to lockup in 1981 to help with gas mileage. Set up correctly lockup only comes on in 4th gear at 45mph or higher, so why not use it? Gas is expensive so why not get the best MPG you can, this is a street car right? There is no disadvantage having it that I know of, if you are lugging the engine you will be dropping out of 4th gear anyway.

Your car so build it as you want, I try to take advantage of somewhat modern advances.

 

It's the overdrive! Trying to get more turns out than you put in, causes an increased speed differential between the converter components. That energy is converted to heat. And lot's of it!

 

I run the GM 2200 Corvette stall and it works great. My car is about 3450 lbs,engine about 340 hp. I have a manual lock up switch like you. With a 3:42 ratio and 29 inch tires it turns 1950 at 70 MPH locked up. I dont usually lock it up below 60 mph. With a manual lock up its like having a 5 speed automatic

 

One thing I can know without even looking, you don't have a 700r4 from a 90s monte carlo.

 

I know in the off topic LS1 world, both Circle-D and Yank make very high quality and highly regarded converters for the 6l80e which essentially is a computerized 700r. I personally have a 2800 stall converter for my Silverado and am very happy. Other mods to avoid excessive heat are a transgo HD2 shift kit as well as corvette 2nd gear servos and a billet 4th gear servo. Really nice firm shifts and gear holding IMHO. Hope this helps


Posted from the TJJ App for iPhone & iPad

 

Just because "that's ALL they work on" doesn't mean they're good at it.

 

#1 most important thing is to set up the TV cable correctly. #2 most important thing is keep it running cool.

 

Actually this is wrong. At least the dual-coupling design used from 1956-1964 would lock up, it didn't really have a torque converter per-se although it looks like one in there. That's how my '60 Pontiac would pull almost 20 MPG with a big 389.

You take away lock-up you make the trans less efficient and lose power. I sincerely doubt you'll pull 30 MPG with it. The 283 won't have enough low end to pull at 1500 RPM at speed. Even a 350 isn't that great at low RPM.

But good luck and run an auxillary trans cooler.

 

Do you know what stall a dead stock converter would have?
Jay

 

Lock up is a must. I first intstalled a 200R without it and ended up putting one in later. I run the B & M adjustable lock up control and it works great.

 

Thanks - claiming no knowledge Limey on that. What ever it is from it works great

 

Hahahahaha .....
Man! You'd argue with yourself, regardless of the subject, if we weren't around, huh?
Poor guy ...

 

Impossible to know for sure but the 87 trans am unit in the Buick will flash to around 1800, stall is probably around 1500.

 

1400- 2000, depending on what impeller and stator used...notated by the original 3 digit code

 

1800, or close to it.

 

I've been running 700s in a few cars now since the $4+ gas crisis in '08. Have used them well over 150,000 miles just to give reference. Another 750 miles towing this week and another planned 1,000+ trip towing next week. All with a 700 in my GTO pulling a trailer with a car or a boat on it.
Further, the majority of these miles were towing. Just last month, I towed 4,000 miles with it and I do not use the lock up or any electronics at all. Theses trans have held up wonderfully in a few of my cars, towing without using the lock up.

Towing w/700r4 for work-



Towing w/700r4 for (much) pleasure-



Based on this, I cannot agree that you MUST use the lock up. I am sure it may be a good idea but, know personally it is not required. You will not burn it up by not using it. I live in Phoenix and tow a lot so, I would have as much heat issues as anyone and I go through a lot of mountain grades too.
Now, I am not saying not to use the lock up, I am simply saying, you do not HAVE to.

I run a good size cooler, a deep alum pan and a temp gauge. My trans rarely sees over 190 and normally runs 170 without a lock up and while towing.
I have run most versions including an early '86 version but, of course, the later ones with the aux valve body are better units.

Adding the lock up effectively gives you a 5th forward gear ( as far as the engine is concerned ). So, if you could benefit from that '5th' gear, it is a simple wire and toggle as some have mentioned but, important to run that wire through a cruise control type brake light switch. That way, you do not have to think about hitting your toggle if you have to do a panic stop.
best to you
These are really great transmissions. I realize you did not ask about towing with one but, showing what I am doing while not using a lock up and towing, shows you can easily do the same or less. Just sharing what works for me- day in and day out. I have no other vehicle in use so, I depend on this vehicle and its 700r4.

 

You're never suppose to use lock-up when towing or under a heavy load situation. Using lock-up while towing or heavy load will kill any overdrive regardless of manufacturer.

However not using a lock-up in a "no-load" situation, such as cruising, can also hurt and/or kill an overdrive.

Any competent tranny builder will tell you that.

 

I'm running a 1990 700R4, Trans-go shift kit, Raybestos Z-pak, Corvette servo. Behind a 383 w/cam, 600 Edelbrock. In front of
8" Ford 4:11 w/trac-loc.
I'm using an 1800-2000 stall converter WITH 4th gear lockup.
Connect out-side front pin on trans to 12 volts. You can hear it lock a second after the last shift. Works Great in my '29 pickup! (2400 lbs.) 75 mph @ 2400 rpm.

 

Applekrate....thank you for the info. I am the one with the fleetline that is not going to run a lock up torque converter with my 283 and 700R.

I talked with a large torque converter manufg co and they also said no problem not running a lock up...but they recommended using a trans go part for correct fluid circulation....

The guy who is going to re do my trans first mentioned it and said he has lots of 700R's out there without lock up and he has been building these trans for years.

Your post just confirms his sayings. I am just thinking if a turbo 350 and 400 have NO lock up....and you modify a 700R to be like them, why would you have problems....different metal? I think not.

 

Asking advice on a transmission from a front wheel drive monte carlo. People just don't know what they don't know anymore.

Golly, when does overdrive kick in on this th350? It is made from the same kind of metal after all. Next up, I'm gonna put 305 pistons in a 400 for better gas mileage. They'll fit. They are the same kind of metal.

 

From another site ....there were several simular posts....but here is a couple of trans guys who states the same thing my trans guy told me...and the torque converter company told me....

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 [COLOR=blue !important][COLOR=blue !important]vehicle[/COLOR][/COLOR]). 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.<!-- google_ad_section_end -->

<TABLE border=0 cellSpacing=0 cellPadding=6 width="100%"><TBODY><TR><TD style="BORDER-BOTTOM: 1px inset; BORDER-LEFT: 1px inset; BORDER-TOP: 1px inset; BORDER-RIGHT: 1px inset" class=alt2>Pro Built Automatics: 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. </TD></TR></TBODY></TABLE>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.<!-- google_ad_section_end -->

and.....53 SLED....When you build a 305 and put it in a 51 shoebox your have built from the ground up and you have driven it for 8 years without turning a wrench and it gets nearly 25MPG running 70 plus in the mountains without overdrive and a 279 rear.....YOU LET ME KNOW OKAY....!!!

 

-------------------------------------------------------------------------------------------

Using your brain.....I guess 4th gear is made of rubber and completely different than 1st, 2nd, and 3rd.

WOW!!!!!!!!!!!!

 

Spoken and acting like a true & typical plastic Chevy owner.

 

Put a 200-4R in our 50 Chevy with ZZ3 motor and 3.73 rear. Lockup only in 4th gear through adjustable vacuum switch control. Works great. The converter is around 2200 stall. Think we could have gone lower.

 

I am guessing that the old fords and chevys that had overdrive in the 50's had a magical gear......

That when you put them in overdrive ( which is what..and made out of what....????) the transmission oil got hot and magically dissappeared and the trans would all burn out......

Gee....like the bumper stickers say....."Critical thinking-the other national deficit".

 

Medication time.... medication time!

 

I did not start this .....but sometimes stupidity and ignorance gets to me and needs a response....

I'll ask you !!!.....What is so magical about an overdrive gear? How does it make the transmission heat up and ruin?

Before you answer.....please read the comments from two different transmission specialist and keep in mind what my transmission specialist said...and what the huge torque converter manufacture company tech people told me and what the trans-go people told me....etc etc etc.

 

Dude... That guy likes to argue with anyone and everyone over nothing. I know it's difficult, but most of us have learned to simply ignore him.