700r4 Guys - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jbristo67 · 03-22-2009, 09:02 PM

I was going to run a 700 a while back. Some where I was looking through a parts catalog and I saw an electric deal that you hooked a vacuum line to and then it plugged into and ran your lock up on your tranny Does any one know what I am talking about and if so where do I find one?? I have looked every where and I am drawing a complete blank

**LEEVON** · 03-22-2009, 09:46 PM

You're talking about a vacuum switch, can get them from GM or the junkyard. If your trans is wired for lock-up internally, then you just need the vacuum switch and brake cancel switch for a factory-like lock-up. Part #'s are here:

http://www.73-87.com/7387garage/drivetrain/lockup.htm

**Boog** · 03-22-2009, 09:55 PM

Or for a little less $ you can use the kit from Bowtie Overdrives.

jbristo67 · 03-22-2009, 10:42 PM

I have an electric lock up on my th350 will that work for that too

**americanmusc1e** · 03-22-2009, 11:31 PM

if you don't want to spend a lot of money you can google "700r4 lockup wiring" and find out how to do it yourself, I just did mine but i used a toggle switch

jbristo67 · 03-23-2009, 01:33 AM

What if I just Dont hook it up

**americanmusc1e** · 03-24-2009, 09:18 AM

Quote:

Originally Posted by jbristo67

What if I just Dont hook it up

from what i heard the transmission has to lock in fourth gear or it can cause overheating problems, lock it up

smoky02 · 03-24-2009, 09:39 AM

I had a 700R4 that had a valve installed by a transmission guy, he swore up and down that it would lock up by itself and didn't need any other supporting equipment. Long story short, the tranny never locked up while me and my dad went on the hot rod power tour. Although the truck was always hot it never overheated. About 3,000 miles in 4 days.

6772owner · 03-24-2009, 11:03 AM

I would use the lock up feature, it is the reason to have the 700 because it drops the revs when it locks and makes for a little engine braking at speed. Jet Performance sells a kit to do the vacuum set up you are asking about. I have it on my truck, never a problem for me.

smoky02 · 03-24-2009, 11:05 AM

You don't have to use the vacuum set-up, but I would suggest at least running a break switch. I bought a cheap lock-up kit from my local transmission shop, it came with crude instructions, and I also bought a cruise control brake switch. I ran the two in series and mine is working wonderfully, and has been for about 6 months.

MrC1 · 03-24-2009, 11:33 AM

I don't get the brake swith idea. Why would you want to unlock just cause you tapped the brakes? Am I missing something?

I wired mine to a lighted switch on the dash. Now it locks up when it shifts into OD.....if I have the switch on.

You will want the lockup. Run around a little without it, then install it. That way you'll really appreciate the difference. It's awesome.

**nightmare** · 03-24-2009, 02:23 PM

this is what i did:
http://www.67-72chevytrucks.com/vboa...94&postcount=7

Andy4639 · 03-24-2009, 03:15 PM

I had all this vacum stuff with brake switch and took it all off and have just the toggle switch on the dash. Has over 150,000 miles on it so far and not one problem.

**SactoJim** · 03-24-2009, 03:52 PM

Quote:

Originally Posted by MrC1

I don't get the brake swith idea. Why would you want to unlock just cause you tapped the brakes? Am I missing something?

I wired mine to a lighted switch on the dash. Now it locks up when it shifts into OD.....if I have the switch on.

You will want the lockup. Run around a little without it, then install it. That way you'll really appreciate the difference. It's awesome.

If you have it set up with an "on / off" switch only and forget to unlock the converter before you come to a stop, it'll will kill the engine without a brake switch.

smoky02 · 03-24-2009, 03:57 PM

It doesn't kick out of lockup when the transmission downshifts as the vehicle slows down?

blazer72 · 03-24-2009, 08:06 PM

I went with TCI's lockup kit - the best way to go IMO. Not the cheapest. Kit cost $100, but worth it. I don't do well with manual switches - to forgetful.

**LEEVON** · 03-24-2009, 11:39 PM

Quote:

Originally Posted by Boog

Or for a little less $ you can use the kit from Bowtie Overdrives.

I put the vacuum and brake switch on the counter at the junkyard and the guy looked at it, said "what the hell is that?" and "take it". So it was FREE. If his trans is already wired internally, then that's all you need for a factory installation. I just don't get these $100+ kits, lots of them come with the internal wiring which is usuall already there.

MrC1 · 03-27-2009, 08:44 PM

Quote:

Originally Posted by SactoJim

If you have it set up with an "on / off" switch only and forget to unlock the converter before you come to a stop, it'll will kill the engine without a brake switch.

Not true. I can't seem to remember what unlocks it, but I have nothing more than the switch on the dash and have no issues with it staying locked. As soon as ou leave OD it's no longer locked in fact.

**americanmusc1e** · 03-27-2009, 08:54 PM

Quote:

Originally Posted by MrC1

Not true. I can't seem to remember what unlocks it, but I have nothing more than the switch on the dash and have no issues with it staying locked. As soon as ou leave OD it's no longer locked in fact.

mine locks in 3rd too but i don't have a brake switch and so far no problems

jugernot · 03-27-2009, 09:42 PM

I have often thought about switching to a 700r4 transmission.

Since then I have seen many questions regarding coverting to a 700r4.

Maybe a Moderator, or a 700R4 Expert could put together a complete HOW TO for converting to a 700R4? Including fixes for the many problems incountered with the swap.

I know that it would really help me and many others.

Please excuse this post if one already exsist.

67ChevyRedneck · 03-27-2009, 09:44 PM

I had the TCI kit on mine years ago and it didn't have the brake switch. Some knucklehead pulled out in front of me from a side street years ago and I slammed the brakes on while the truck was in 4th gear with the TC locked. The engine died. Thankfully the guy pulled out fast enough that I missed him but it took the truck forever to roll to a stop. I added the BTO kit with a brake switch and have had a few "panic stops" in 4th gear with the TC locked and it hasn't stalled (because the brake switch unlocked the TC when I hit the brakes).

I doubt that if a deer runs out in front of you or a car pulls out in front of you at cruising speed that you'll remember to hit the button/switch to unlock the TC

**Boog** · 03-27-2009, 10:36 PM

Good enough reason right there to do it right.

100mph · 03-28-2009, 11:23 AM

Hi - this was a very helpful read, perhaps someone could help me out a little though.

I'm just about to have a 700R4 put in my 69 and 'my guy' is telling just to not worry about the lockup and everything will be fine.

I'd appreciate others opinions on not hooking it up but also I'm a bit new to all this and perhaps really don't fully understand what the lockup torque converter does and whether or not I'd regret not hooking it up.

I read a comment a little further up about how great it is but why??

Thanks!!

03-22-2009, 09:02 PM	#1
jbristo67 resident oilfield trash Join Date: Jan 2009 Location: Lubbock TX Posts: 1,465	700r4 Guys I was going to run a 700 a while back. Some where I was looking through a parts catalog and I saw an electric deal that you hooked a vacuum line to and then it plugged into and ran your lock up on your tranny Does any one know what I am talking about and if so where do I find one?? I have looked every where and I am drawing a complete blank __________________ 1967 SWB C10 396/400 factory air factory tach (sadly had to send to a new home) 1986 Honda 70 Fourtrax 1991 Chevrolet K5 blazer 2wd 1982 Mastercraft Pro Star 190 Stars and Stripes 2002 Chevrolet Tahoe 2011 Nissan Armada

03-22-2009, 09:46 PM	#2
LEEVON Moderator Join Date: Jul 2006 Location: Ozark, MO Posts: 4,895	Re: 700r4 Guys You're talking about a vacuum switch, can get them from GM or the junkyard. If your trans is wired for lock-up internally, then you just need the vacuum switch and brake cancel switch for a factory-like lock-up. Part #'s are here: http://www.73-87.com/7387garage/drivetrain/lockup.htm __________________ '86 GMC C30 Crew ~ '86 C20 Crew ~ '79 K15 Sierra Grande ~ '76 Blazer 2wd ~ '74K10 ~ '71 Cheyenne swb ~'50 3100 bagged ~ '80 Wife ~ Late model kids

03-22-2009, 09:55 PM	#3
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 13,559	Re: 700r4 Guys Or for a little less $ you can use the kit from Bowtie Overdrives. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

03-22-2009, 10:42 PM	#4
jbristo67 resident oilfield trash Join Date: Jan 2009 Location: Lubbock TX Posts: 1,465	Re: 700r4 Guys I have an electric lock up on my th350 will that work for that too __________________ 1967 SWB C10 396/400 factory air factory tach (sadly had to send to a new home) 1986 Honda 70 Fourtrax 1991 Chevrolet K5 blazer 2wd 1982 Mastercraft Pro Star 190 Stars and Stripes 2002 Chevrolet Tahoe 2011 Nissan Armada

03-22-2009, 11:31 PM	#5
americanmusc1e Senior Member Join Date: Jan 2009 Location: Austin, TX Posts: 1,079	Re: 700r4 Guys if you don't want to spend a lot of money you can google "700r4 lockup wiring" and find out how to do it yourself, I just did mine but i used a toggle switch __________________ -- Josh Instagram: @americanmusc1e OLD SKOOL-- 1970 C10. 454/Th400/3.07 posi Build Thread FARM TRUCK----1949 Chevrolet 3800 Power Wagon Hauler Build Thread 1999 4wd OBS Tahoe - daily. DM me if you can't see photos i posted

03-23-2009, 01:33 AM	#6
jbristo67 resident oilfield trash Join Date: Jan 2009 Location: Lubbock TX Posts: 1,465	Re: 700r4 Guys What if I just Dont hook it up __________________ 1967 SWB C10 396/400 factory air factory tach (sadly had to send to a new home) 1986 Honda 70 Fourtrax 1991 Chevrolet K5 blazer 2wd 1982 Mastercraft Pro Star 190 Stars and Stripes 2002 Chevrolet Tahoe 2011 Nissan Armada

03-24-2009, 09:39 AM	#8
smoky02 Registered User Join Date: Oct 2003 Location: Sunny, Florida, some might call it South Alabama Posts: 834	Re: 700r4 Guys I had a 700R4 that had a valve installed by a transmission guy, he swore up and down that it would lock up by itself and didn't need any other supporting equipment. Long story short, the tranny never locked up while me and my dad went on the hot rod power tour. Although the truck was always hot it never overheated. About 3,000 miles in 4 days. __________________ Just sold my C10...sad day... Looking for a 1972 Blazer to hopefully fill the hole in my heart.

03-24-2009, 11:03 AM	#9
6772owner Gearhead Join Date: Jan 2008 Location: Colorado Posts: 1,193	Re: 700r4 Guys I would use the lock up feature, it is the reason to have the 700 because it drops the revs when it locks and makes for a little engine braking at speed. Jet Performance sells a kit to do the vacuum set up you are asking about. I have it on my truck, never a problem for me. __________________ 2002 Saturn SL2, My D/D 2019 Ford Fusion SE, Ecoboost - Wife's D/D 1993 Camaro Z28, A4, CAI, Cat-Back Exhaust Project C10 (my 72' C10 w/96' LT1, 700R4, bagged F&R, 18's (for now), Short/Fleet) -- SOLD! Build Thread: http://67-72chevytrucks.com/vboard/s...d.php?t=313644

03-24-2009, 11:05 AM	#10
smoky02 Registered User Join Date: Oct 2003 Location: Sunny, Florida, some might call it South Alabama Posts: 834	Re: 700r4 Guys You don't have to use the vacuum set-up, but I would suggest at least running a break switch. I bought a cheap lock-up kit from my local transmission shop, it came with crude instructions, and I also bought a cruise control brake switch. I ran the two in series and mine is working wonderfully, and has been for about 6 months. __________________ Just sold my C10...sad day... Looking for a 1972 Blazer to hopefully fill the hole in my heart.

03-24-2009, 11:33 AM	#11
MrC1 Dork For Days Join Date: Aug 2005 Location: Dallas Posts: 407	Re: 700r4 Guys I don't get the brake swith idea. Why would you want to unlock just cause you tapped the brakes? Am I missing something? I wired mine to a lighted switch on the dash. Now it locks up when it shifts into OD.....if I have the switch on. You will want the lockup. Run around a little without it, then install it. That way you'll really appreciate the difference. It's awesome. __________________ 1972 C20, 402/700R4 - My first classic truck, bought in September 2005. 85% transformed from "Farm" to "Cool" status! 1970 Dodge Challenger 440, 4sp (my other toy) 12.67 @ 117 MPH, with a pathetic 2.022 60' 2007 Dodge Charger SRT-8 2008 Cadillac CTS All-American garage, baby!

03-24-2009, 03:15 PM	#13
Andy4639 Old member Join Date: Jan 2002 Location: Liberty, & Garden City S.C. , U.S. Posts: 19,945	Re: 700r4 Guys I had all this vacum stuff with brake switch and took it all off and have just the toggle switch on the dash. Has over 150,000 miles on it so far and not one problem. __________________ 1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.

03-24-2009, 03:57 PM	#15
smoky02 Registered User Join Date: Oct 2003 Location: Sunny, Florida, some might call it South Alabama Posts: 834	Re: 700r4 Guys It doesn't kick out of lockup when the transmission downshifts as the vehicle slows down? __________________ Just sold my C10...sad day... Looking for a 1972 Blazer to hopefully fill the hole in my heart.

03-24-2009, 08:06 PM	#16
blazer72 Freedom isn't Free Join Date: Oct 2006 Location: OKC Posts: 393	Re: 700r4 Guys I went with TCI's lockup kit - the best way to go IMO. Not the cheapest. Kit cost $100, but worth it. I don't do well with manual switches - to forgetful.

03-27-2009, 09:42 PM	#20
jugernot Life, Be In It..... Join Date: Oct 2003 Location: Novato, California Posts: 1,498	Re: 700r4 Guys I have often thought about switching to a 700r4 transmission. Since then I have seen many questions regarding coverting to a 700r4. Maybe a Moderator, or a 700R4 Expert could put together a complete HOW TO for converting to a 700R4? Including fixes for the many problems incountered with the swap. I know that it would really help me and many others. Please excuse this post if one already exsist. __________________ Project Name: LEMON DROP. Reconstruction started "December 2000". Projected completion date "Who knows" http://67-72chevytrucks.com/vboard/s...d.php?t=200082 Last edited by jugernot; 03-27-2009 at 09:43 PM.

03-27-2009, 09:44 PM	#21
67ChevyRedneck Hittin E-Z Street on Mud Tires Join Date: Nov 2004 Location: Greenville, SC Posts: 23,090	Re: 700r4 Guys I had the TCI kit on mine years ago and it didn't have the brake switch. Some knucklehead pulled out in front of me from a side street years ago and I slammed the brakes on while the truck was in 4th gear with the TC locked. The engine died. Thankfully the guy pulled out fast enough that I missed him but it took the truck forever to roll to a stop. I added the BTO kit with a brake switch and have had a few "panic stops" in 4th gear with the TC locked and it hasn't stalled (because the brake switch unlocked the TC when I hit the brakes). I doubt that if a deer runs out in front of you or a car pulls out in front of you at cruising speed that you'll remember to hit the button/switch to unlock the TC __________________ Jesse James 1967 C10 SWB Stepside: 350/700R4/3.73 1965 Ford Mustang: 289/T5-5spd/3.25 Trac-Loc 1968 Pontiac Firebird: Project Fire Chicken! 2015 Silverado Double Cab 5.3L Z71 2001 Jeep Wrangler Sport 4.0L 5spd 2020 Chevrolet Equinox Premium 2.0L Turbo 2011 Mustang V6 ~ Wife's ride American Born, Country by the Grace of God 1967 CST Shop Truck Rebuild! My 1967 C-10 Build Thread My Vintage Air A/C Install Project "On a Dime" Trying my hand at Home Renovation! 1965 Mustang Modifications! Last edited by 67ChevyRedneck; 03-28-2009 at 12:24 AM.



Register or Log In To remove these advertisements.

03-27-2009, 10:36 PM	#22
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 13,559	Re: 700r4 Guys Good enough reason right there to do it right. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

03-28-2009, 11:23 AM	#23
100mph Registered User Join Date: Jul 2008 Location: Lewiston NY Posts: 70	Re: 700r4 Guys Hi - this was a very helpful read, perhaps someone could help me out a little though. I'm just about to have a 700R4 put in my 69 and 'my guy' is telling just to not worry about the lockup and everything will be fine. I'd appreciate others opinions on not hooking it up but also I'm a bit new to all this and perhaps really don't fully understand what the lockup torque converter does and whether or not I'd regret not hooking it up. I read a comment a little further up about how great it is but why?? Thanks!!

Register or Log In To remove these advertisements.