700r4 TCC vacuum switch - The 1947 - Present Chevrolet & GMC Truck Message Board Network

trucks72 · 03-02-2010, 09:47 AM

Does anybody know where a person can buy these new? GM has discontinued the part number I have. And I have used all the ones that I can find in juckyards around here.

cdowns · 03-02-2010, 10:23 AM

try calling bowtie overdrives or painless wiring and see if they have anything

**nightmare** · 03-02-2010, 11:35 AM

gm #8627332? i just ordered it from globalgmparts.com. they called me to tell me that it was discontinued, but the guy i talked to, smitty, said he could still get it. here is the number - 908 757 4000, his extension is 409

**michael bustamante** · 03-02-2010, 12:19 PM

I went to a local aamco and picked one up for 40 bucks, new (GM oldstock) they told me they buy the overstock and discontinued stuff from GM

Chevydude56 · 03-02-2010, 12:37 PM

Found these
Ebay
http://cgi.ebay.com/ebaymotors/212-3...item3efd2588b8

amazon

Amazon.com: ACDelco 212-331 Switch Assembly:...

bamabaxter · 03-02-2010, 01:03 PM

I recommend buying an adjustable one.

trucks72 · 03-02-2010, 07:59 PM

Thanks, I will take the part number off the one on ebay and call my Gm dealer tomorrow. I went to the another junk yard today and found 2. But I could use some more. Have alot of people ask to do this to their trans. I did this to one 2wd drive Blazer one time. Guy drove to Atlanta in it. doing 75-80 and got 23 mpg. Thanks to everyone.

tqlspec · 03-02-2010, 08:24 PM

trucks72...
How is this TCC vacuum swithch being used on the 700r4?

bamabaxter · 03-02-2010, 08:33 PM

he is using it to automatically lock up the converter when he reaches steady speed in 4th gear. If you have ever watched a vacuum gauge as you drive, when you reach cruising speed the vacuum goes up since you don't have the butterflies open as much. This high vacuum signal will engage the TCC and lock it in, when he steps on the gas to pass, the sudden drop in vacuum will dis-engage the clutch in the torque converter.

tqlspec · 03-02-2010, 08:48 PM

does this improve fuel mpg at highway speeds? My 72' C-10 could certainly use it.

cparman · 03-02-2010, 09:24 PM

I hard wire mine. From the connector at the trans, to a 4 wire stop light switch. Two of the connectors on the stop lite sw. are for the brakes, and are normally open, the other two are to disengage the factory cruise control. I wsire the TCC to the cruise side if this switch. SO< when you are cruising 45+ and you apply the brake the torque converter UNLOCKS. I also wire a toggle switch in line with this so I can manually unlock the converter if I want to. Simple, and it flat works

bamabaxter · 03-02-2010, 11:49 PM

That is the way that I wired mine. Yes it helps with gas mileage...dropped my rpms about 250-300 at freeway speeds.

trucks72 · 03-02-2010, 11:57 PM

That is exactly the way I wired mine. This is how chevrolet done it for years on some of their stuff. It is a cheap and easy way of doing it. I use the brake switch on mine, but some guys do not use it. They just lock the torque convertor in 4th gear only. When it shifts down it will unlock. My fear with that is if yiou hit the brakes really fast it will stall motor. Never tried it that way so I can not say honestly. But the way I see it if it works why mess with it. Simple and not expensive. Payed $20 for 2 switches today.

bamabaxter · 03-03-2010, 08:49 AM

I actually mounted another dimmer switch on the floor so that I can engage mine by foot and still keep my arm around my honey while drivin'.....

2ndCIB · 03-03-2010, 10:46 AM

Summit sells one that is adjustable for @ $80. It comes with instructions to mount it on the side of the tranny but i used longer wires and vacuum line and put it out of sight under the dash and left the allen wrench in it to adjust it "on the fly". I also put a "on-off-on" toggle switch in so I can select auto lockup, lockup off, or locked. It sure is nice to get your tranny to do what you want without a computer.

gkesseru · 03-03-2010, 08:09 PM

2ndCIB: Do you have a wiring diagram for that on-off-on switch setup?

2ndCIB · 03-04-2010, 05:39 PM

Dont have a diagram but here it goes. There are three wires that come out of the plug on the transmission. One Power, One Ground and One "Overide" to lock the converter at any speed. I used a ON-OFF-ON toggle switch. Use the ground side to controll what you want to do by grounding the center terminal (off Position). Hook the ground from the tranny plug to one of the "ON" sides of the toggle switch. Hook the "Override" to the other "ON" terminal. Flip the switch one way and it is automatic by going through the vacuum switch. In the center position it takes away the ground and the converter will not lock up. In the other "on" position it grounds the switch and locks the converter. I know this sounds confusing but when you see the diagram it will kinda make sense (I hope). I used a small toggle from radio shack and mounted it in the hole under the edge of the dash right above the brake release. This keeps the switch out of sight and still in easy reach. I extended the wires from the transmission to under the dash next to the steering column. I ran a vacuum source under the dash and hooked up the adjustable vacuum switch. The switch its self is about an inch an a half square and about a quarter inch thick. It has two wires and a vacuum port with an adjustment screw in the side. I superglued an allenwrench in the adjustment so i can adjust it going down the road. It works pretty well once it is adjusted. Sure does feel good to here the RPM dorp on demand. Hope this helps.

cparman · 03-04-2010, 07:19 PM

Dude you are really really smooth!!! I bet she was sitting next to you when you wrote that! I do like the dimmer switch idea, might try that on mine!! HA HA

Quote:

Originally Posted by bamabaxter

I actually mounted another dimmer switch on the floor so that I can engage mine by foot and still keep my arm around my honey while drivin'.....

bamabaxter · 03-04-2010, 08:56 PM

It is the way to go....much easier to have a Dr.Pepper while driving than have to reach down and flip a switch....my opinion. She wasn't next to me, but she would agree, I can assure you. I can honestly say that I am lucky to have a wife that likes my truck almost more than me.....especially since she can ride "middle" on the bench.....now every vehicle has a dang console.

2ndCIB · 03-05-2010, 09:29 AM

Im trying to get mine used to seeing me flip a switch. That way it will look normal until the ejection seat goes off.

bamabaxter · 03-05-2010, 11:38 AM

03-02-2010, 09:47 AM	#1
trucks72 trucks72 Join Date: Jul 2002 Location: Crossville Posts: 315	700r4 TCC vacuum switch Does anybody know where a person can buy these new? GM has discontinued the part number I have. And I have used all the ones that I can find in juckyards around here.

03-02-2010, 10:23 AM	#2
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: 700r4 TCC vacuum switch try calling bowtie overdrives or painless wiring and see if they have anything __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

03-02-2010, 12:19 PM	#4
michael bustamante Senior Member Join Date: Sep 2007 Location: Albuquerque NM Posts: 7,814	Re: 700r4 TCC vacuum switch I went to a local aamco and picked one up for 40 bucks, new (GM oldstock) they told me they buy the overstock and discontinued stuff from GM __________________ 1967custom

03-02-2010, 12:37 PM	#5
Chevydude56 Registered User Join Date: Sep 2009 Location: Syracuse NY Posts: 110	Re: 700r4 TCC vacuum switch Found these Ebay http://cgi.ebay.com/ebaymotors/212-3...item3efd2588b8 amazon Amazon.com: ACDelco 212-331 Switch Assembly:... __________________ 1967 Suburban 292 3spd 1964 Chevy II wagon 1971 Monte Carlo 402BB 1964 Cadillac series 62 2dr 1964 Bonneville 2dr/ht 1967 GTO 1978 Chevy Van 30 1989 R30 Crew Dually Bonus Cab Last edited by Chevydude56; 03-02-2010 at 12:39 PM.

03-02-2010, 01:03 PM	#6
bamabaxter Registered User Join Date: Mar 2008 Location: Clinton, MS Posts: 545	Re: 700r4 TCC vacuum switch I recommend buying an adjustable one. __________________ '72 Chevy C10 383, 700r4, 3.73's A little rust never hurt anyone. I consider it weight reduction.

03-02-2010, 07:59 PM	#7
trucks72 trucks72 Join Date: Jul 2002 Location: Crossville Posts: 315	Re: 700r4 TCC vacuum switch Thanks, I will take the part number off the one on ebay and call my Gm dealer tomorrow. I went to the another junk yard today and found 2. But I could use some more. Have alot of people ask to do this to their trans. I did this to one 2wd drive Blazer one time. Guy drove to Atlanta in it. doing 75-80 and got 23 mpg. Thanks to everyone.

03-02-2010, 08:24 PM	#8
tqlspec Registered User Join Date: Feb 2008 Location: Jackson, TN Posts: 99	Re: 700r4 TCC vacuum switch trucks72... How is this TCC vacuum swithch being used on the 700r4?

03-02-2010, 08:33 PM	#9
bamabaxter Registered User Join Date: Mar 2008 Location: Clinton, MS Posts: 545	Re: 700r4 TCC vacuum switch he is using it to automatically lock up the converter when he reaches steady speed in 4th gear. If you have ever watched a vacuum gauge as you drive, when you reach cruising speed the vacuum goes up since you don't have the butterflies open as much. This high vacuum signal will engage the TCC and lock it in, when he steps on the gas to pass, the sudden drop in vacuum will dis-engage the clutch in the torque converter. __________________ '72 Chevy C10 383, 700r4, 3.73's A little rust never hurt anyone. I consider it weight reduction.

03-02-2010, 08:48 PM	#10
tqlspec Registered User Join Date: Feb 2008 Location: Jackson, TN Posts: 99	Re: 700r4 TCC vacuum switch does this improve fuel mpg at highway speeds? My 72' C-10 could certainly use it.

03-02-2010, 09:24 PM	#11
cparman sharp as a marble Join Date: Jan 2007 Location: atlantic beach,florida Posts: 1,082	Re: 700r4 TCC vacuum switch I hard wire mine. From the connector at the trans, to a 4 wire stop light switch. Two of the connectors on the stop lite sw. are for the brakes, and are normally open, the other two are to disengage the factory cruise control. I wsire the TCC to the cruise side if this switch. SO< when you are cruising 45+ and you apply the brake the torque converter UNLOCKS. I also wire a toggle switch in line with this so I can manually unlock the converter if I want to. Simple, and it flat works

03-02-2010, 11:49 PM	#12
bamabaxter Registered User Join Date: Mar 2008 Location: Clinton, MS Posts: 545	Re: 700r4 TCC vacuum switch That is the way that I wired mine. Yes it helps with gas mileage...dropped my rpms about 250-300 at freeway speeds. __________________ '72 Chevy C10 383, 700r4, 3.73's A little rust never hurt anyone. I consider it weight reduction.

03-02-2010, 11:57 PM	#13
trucks72 trucks72 Join Date: Jul 2002 Location: Crossville Posts: 315	Re: 700r4 TCC vacuum switch That is exactly the way I wired mine. This is how chevrolet done it for years on some of their stuff. It is a cheap and easy way of doing it. I use the brake switch on mine, but some guys do not use it. They just lock the torque convertor in 4th gear only. When it shifts down it will unlock. My fear with that is if yiou hit the brakes really fast it will stall motor. Never tried it that way so I can not say honestly. But the way I see it if it works why mess with it. Simple and not expensive. Payed $20 for 2 switches today.

03-03-2010, 08:49 AM	#14
bamabaxter Registered User Join Date: Mar 2008 Location: Clinton, MS Posts: 545	Re: 700r4 TCC vacuum switch I actually mounted another dimmer switch on the floor so that I can engage mine by foot and still keep my arm around my honey while drivin'..... __________________ '72 Chevy C10 383, 700r4, 3.73's A little rust never hurt anyone. I consider it weight reduction.

03-03-2010, 10:46 AM	#15
2ndCIB Registered User Join Date: Apr 2008 Location: Cale, Arkansas Posts: 29	Re: 700r4 TCC vacuum switch Summit sells one that is adjustable for @ $80. It comes with instructions to mount it on the side of the tranny but i used longer wires and vacuum line and put it out of sight under the dash and left the allen wrench in it to adjust it "on the fly". I also put a "on-off-on" toggle switch in so I can select auto lockup, lockup off, or locked. It sure is nice to get your tranny to do what you want without a computer.

03-03-2010, 08:09 PM	#16
gkesseru Registered User Join Date: Dec 2009 Location: California, Maryland Posts: 544	Re: 700r4 TCC vacuum switch 2ndCIB: Do you have a wiring diagram for that on-off-on switch setup? __________________ 72 Fleet (died) 78 Step (sold) 55 Step named Fred (sold) 00 F150 68 Step (named El Scorcho by PO) Build thread for the new El Scorcho http://67-72chevytrucks.com/vboard/s...d.php?t=392932



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03-04-2010, 05:39 PM	#17
2ndCIB Registered User Join Date: Apr 2008 Location: Cale, Arkansas Posts: 29	Re: 700r4 TCC vacuum switch Dont have a diagram but here it goes. There are three wires that come out of the plug on the transmission. One Power, One Ground and One "Overide" to lock the converter at any speed. I used a ON-OFF-ON toggle switch. Use the ground side to controll what you want to do by grounding the center terminal (off Position). Hook the ground from the tranny plug to one of the "ON" sides of the toggle switch. Hook the "Override" to the other "ON" terminal. Flip the switch one way and it is automatic by going through the vacuum switch. In the center position it takes away the ground and the converter will not lock up. In the other "on" position it grounds the switch and locks the converter. I know this sounds confusing but when you see the diagram it will kinda make sense (I hope). I used a small toggle from radio shack and mounted it in the hole under the edge of the dash right above the brake release. This keeps the switch out of sight and still in easy reach. I extended the wires from the transmission to under the dash next to the steering column. I ran a vacuum source under the dash and hooked up the adjustable vacuum switch. The switch its self is about an inch an a half square and about a quarter inch thick. It has two wires and a vacuum port with an adjustment screw in the side. I superglued an allenwrench in the adjustment so i can adjust it going down the road. It works pretty well once it is adjusted. Sure does feel good to here the RPM dorp on demand. Hope this helps.

03-04-2010, 08:56 PM	#19
bamabaxter Registered User Join Date: Mar 2008 Location: Clinton, MS Posts: 545	Re: 700r4 TCC vacuum switch It is the way to go....much easier to have a Dr.Pepper while driving than have to reach down and flip a switch....my opinion. She wasn't next to me, but she would agree, I can assure you. I can honestly say that I am lucky to have a wife that likes my truck almost more than me.....especially since she can ride "middle" on the bench.....now every vehicle has a dang console. __________________ '72 Chevy C10 383, 700r4, 3.73's A little rust never hurt anyone. I consider it weight reduction.

03-05-2010, 09:29 AM	#20
2ndCIB Registered User Join Date: Apr 2008 Location: Cale, Arkansas Posts: 29	Re: 700r4 TCC vacuum switch Im trying to get mine used to seeing me flip a switch. That way it will look normal until the ejection seat goes off.

03-05-2010, 11:38 AM	#21
bamabaxter Registered User Join Date: Mar 2008 Location: Clinton, MS Posts: 545	Re: 700r4 TCC vacuum switch __________________ '72 Chevy C10 383, 700r4, 3.73's A little rust never hurt anyone. I consider it weight reduction.

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