How is 700r4 lock up controlled in a 1984?

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HotRodPC

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As far as the TCC Solenoid yep, they're alike and the activation is also alike to the best of my knowledge. I know you can use the same system on both but if they came from the factory with the same system is where I'd question it. Like did it change along the way from a different system or not?
Some 700r4's had multiple pressure switches for both 3rd and 4th lock up, some only had lock up in 4th only. I prefer 3rd and 4th lock up.
 

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The gentleman I bought a 700r4 from, a retiring 40+ year transmission builder said something about 3rd gear lock up... but sorry it fuzzy. I think he said it was a mod... wish I remembered. He had little spurts of downloads, big downloads. Kind of a quite guy, until he wasn't. He lives in the country by Vancouver and dang, I can't wait to buy another transmission from him!
 

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The gentleman I bought a 700r4 from, a retiring 40+ year transmission builder said something about 3rd gear lock up... but sorry it fuzzy. I think he said it was a mod... wish I remembered. He had little spurts of downloads, big downloads. Kind of a quite guy, until he wasn't. He lives in the country by Vancouver and dang, I can't wait to buy another transmission from him!

Yes it can be done. Simply by wiring in an addition pressure switch on the 3rd gear part of the valve body to give the TCC solenoid the OK to lock up. It's not a bad feature to have if you want to use D instead of OD.

Some applications came from the factory that way. Some did not. I do not recall the reason why some models went to 4th lock up only.
 

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Yes it can be done. Simply by wiring in an addition pressure switch on the 3rd gear part of the valve body to give the TCC solenoid the OK to lock up. It's not a bad feature to have if you want to use D instead of OD.

Some applications came from the factory that way. Some did not. I do not recall the reason why some models went to 4th lock up only.
One in my pickup had the two pressure switches, real good thing because you're not always going fast enough to be in overdrive, but you could be close to it and locking the converter will drop the r's down to a more comfortable zone running in 3rd gear. Now my Nova I just hooked it up to a toggle switch, love it, lol..
 

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One in my pickup had the two pressure switches, real good thing because you're not always going fast enough to be in overdrive, but you could be close to it and locking the converter will drop the r's down to a more comfortable zone running in 3rd gear. Now my Nova I just hooked it up to a toggle switch, love it, lol..
Me and a buddy built a 700r4 for a Jag that had a 350 Chevy conversion in it. We also did the toggle switch with brake light kill. The guy loved it too.
 

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Me and a buddy built a 700r4 for a Jag that had a 350 Chevy conversion in it. We also did the toggle switch with brake light kill. The guy loved it too.
It's just nice to be in control of it instead of the tranny, it don't always lockup when you want it to.
 

spanky55amg

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F me, it sounds the 700r4 went through as many changes as Mercedes Benz locking systems between 1996 and 1998. (If you dont know about the MB but understand about the 700r4... you get the reference.)
Okkkkk.... so I connected the thing up on my passenger firewall with yellow and brown wires, and that made the truck run like ****. So I unplugged it.
The thing on the drivers side firewall has always been disconnect. I havent touched it b/c it looks like it has vacuum nipples on both sides of it.

My transmission seems to run fine. I believe that I have all four gears and lock up ALTHOUGH, I dont have anything connected by vacuum to the carb. [except for secondaries of course, and the distributor]

I will tell you that my shifts seem weak and down shifting is almost none existing unless a reduction of speed happens.... but I think I also have ignition issues. (problems of a used truck)

buttttttttt listening to how the transmission works, I fully believe that it is locking up... mechanics, you know what Im talking about. I need to install a tach to verify and this is my next install. So question, can the 700r4 lock up the TC without vacuum?
 

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So question, can the 700r4 lock up the TC without vacuum?
Yes, the solenoid has only two wires a ground and a hot you can hook it up any way you want, all they are is a switch there's also a pressure switch on the VB one activates with vacuum the other with fluid pressure, you can use vacuum I believe that's for 3rd gear(I think) or just 4th gear with the pressure switch, or run the ground wire to the case and the + to a hot source and put a toggle switch on it, very simple however you want it to work.
 

spanky55amg

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This does not have a toggle. I guess I have to get the tach on asap so I can verify a lot of things. And perhaps get on the creeper and trace wiring. Thanks y'all!
 

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They don't come with a toggle it's just an option you can add.
 

spanky55amg

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They don't come with a toggle it's just an option you can add.
Oh yeah, I know. I guess I was saying that at least they didnt half ass that in the truck... haha. Im tired of fixing shotty work.
 

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Oh yeah, I know. I guess I was saying that at least they didnt half ass that in the truck... haha. Im tired of fixing shotty work.
I hear ya, it does get old after awhile, lol..
 

spanky55amg

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dont get me started with the radio and cig lighter wiring............... I might be playing in the dash this weekend while I install a tach. Im just going to screw it to the dash pad for now since that is beat to ****, been repainted with god knows what kind of texture, and where the speaker holes are, they just added some cheapo speaker grill... oh and they painted over the brushed silver trim for the bezel but nothing else, so it looks like crap....................... im beginning to rant and almost went on a list. haha.
 

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