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Username Post: 1939 Resto Mod        (Topic#347377)
Buddy Mewbourne 
Member
Posts: 162

Age: 81
Loc: Talladega, Alabama
Reg: 03-04-04
09-27-17 06:15 PM - Post#2709055    

I Am putting a 350 cu in, with 700r trans in my 39 Chevy 2 door sedan. But without computer. The trany already has a lock up kit installed with solenoid and 2 prong pressure switch. Is there any thing else I need? I have found all kinds of answers, but all are so confusing. Some say I need 2 other switches out side of the transmission. There must be a
"Chevy Talk" expert that can help with my problem. Thanks from Second Bridge.

Second Bridge Garage


 




Shepherd 
Frequent Contributor
Posts: 1229

Loc: Lake George, NY
Reg: 11-11-15
09-27-17 06:31 PM - Post#2709057    
    In response to Buddy Mewbourne

http://readingrat.net/wiring-diagram-for-70 0r4-loc...



 
models916 
Valued Contributor
Posts: 4774

Age: 67
Loc: Addison, IL
Reg: 05-28-10
09-28-17 06:10 AM - Post#2709093    
    In response to Buddy Mewbourne

700r4 needed NO computer from start to 1992-part of 1993. After that they became the (e) model and used a computer to shift. Early models used a hydraulic or electric apply to engage the torque converter. The trans shifted into and out of gears with pressure sensed from the TBI cable and timed by the governor. OD (4th) was hydraulic automatic.



 
65_Impala 
Very Senior Member
Posts: 3991

Reg: 12-29-02
09-28-17 10:03 AM - Post#2709118    
    In response to Buddy Mewbourne

It's confusing because there are so many possible ways to provide the power that locks up the torque converter. About the simplest is using a brake pedal switch so the converter locks whenever the transmission is in 4th gear. Personally, I'm not a fan of this because I would want it to unlock to accelerated without having to be kicked-down to 3rd. But, I won't randomly get into other ways - post how you want it to work and then I can try to give a solution to do what you want.



 
Buddy Mewbourne 
Member
Posts: 162

Age: 81
Loc: Talladega, Alabama
Reg: 03-04-04
09-28-17 06:04 PM - Post#2709159    
    In response to 65_Impala

THANKS FOR YOUR REPLY. I SIMPLY WANT MY 700R TO SHIFT NORMALLY THROUGH ALL GEARS AND HAVE A KICK DOWN PASSING GEAR. LIKE TRANSMISSIONS DID BEFORE THE ADVENT OF COMPUTER TECHNOLOGY. ANY HELP IS APPRECIATED.

Second Bridge Garage


 
raycow 
Honored Member
Posts: 27353
raycow
Loc: San Francisco, CA
Reg: 11-26-02
09-28-17 07:16 PM - Post#2709173    
    In response to Buddy Mewbourne

  • Buddy Mewbourne Said:
THANKS FOR YOUR REPLY. I SIMPLY WANT MY 700R TO SHIFT NORMALLY THROUGH ALL GEARS AND HAVE A KICK DOWN PASSING GEAR.....


Buddy, we seem to have a slight information gap here. If all you want is for the trans to do what you described above, you don't need to have any electrical hookup at all. The control of all four gears is totally hydraulic. You will need to get the TV cable adjustment correct though if you don't want the trans to die an early painful death. Instructions for this adjustment are all over the net.

However, if you want the converter clutch to lock up (and you SHOULD want the clutch to lock up, for both the long term benefit of the trans and better fuel mileage), that's what the electrical hookup is for.

Ray

Those who choose an automatic transmission want transportation. Those who choose a manual transmission want to drive.


 
IgnitionMan 
Valued Contributor
Posts: 3288

Reg: 04-15-05
09-29-17 05:14 AM - Post#2709187    
    In response to Buddy Mewbourne

Buddy, please turn your CAPS lock off on the computer. Thanks.



 
Shepherd 
Frequent Contributor
Posts: 1229

Loc: Lake George, NY
Reg: 11-11-15
09-29-17 11:04 AM - Post#2709212    
    In response to raycow

Ray, agreed on all points, this seems to address his base concerns.



 
Buddy Mewbourne 
Member
Posts: 162

Age: 81
Loc: Talladega, Alabama
Reg: 03-04-04
09-29-17 05:34 PM - Post#2709247    
    In response to Shepherd

Thanks to all that responded to my post. Will make the correct adjustment on TV cable.
Second Bridge Garage

Second Bridge Garage


 
models916 
Valued Contributor
Posts: 4774

Age: 67
Loc: Addison, IL
Reg: 05-28-10
10-03-17 07:48 AM - Post#2709622    
    In response to Buddy Mewbourne

Different years will need different lock up solutions. 1-2-3-4 will all apply based on governor and carb linkage adjustment. The electrical part is to just lock the converter. If you don't lock the converter, you will have to run an aux. trans cooler to compensate for the added heat generated by the OD heat. If you lock the converter, it generates very little heat and will have to pass thru the bottom of your radiator to maintain heat in the trans on long runs.

http://www.crankshaftcoalition.com/wiki/Torque_con...



 
5Larry7 
"14th Year" Gold Supporting Member
Posts: 1924
5Larry7
Loc: Dallas, TX
Reg: 05-17-04
10-03-17 02:00 PM - Post#2709655    
    In response to Buddy Mewbourne

I had the same issue with my 700R4, torque converter lockup as soon as it shifted into overdrive. I got a Compushift Mini and now I can set up when I want the lock up to occur. Check out this link. Nice folks there and very helpful.

https://www.hgmelectronics.com/products-compushift...

'57 210, 327 cid, Holley MPFI, 700R4, A/C & more.
'51 Studebaker Starlite coupe, 350, TH400, GV OD.
'96 Replica of a 1950's Teardrop Trailer.


 
1983G20Van 
Super Senior Member
Posts: 3687

Loc: Bedford, Texas, USA
Reg: 11-13-02
10-03-17 03:03 PM - Post#2709663    
    In response to 5Larry7

My factory 700r4 was non computer controlled. 1982-1986 G-series vans, some S10s and some C10 trucks used a vacuum switch to control the lockup.

In the G-series van GM had lockup in 2nd & 3rd gear controlled by a ported vacuum switch and lockup in 4th gear by a pressure switch in the valve body.

Power is first wired through a Normally Closed brake switch. When the brake pedal is not applied it supplied power to the lockup harness. The lockup harness fed power to the vacuum switch mounted on the radiator core support close to the battery. The switch closed at approximately 5 in/hg and was connected to a ported vacuum port through a thermal vacuum switch in the thermostat housing that blocked the vacuum under about 120*F and a small vacuum delay valve that delayed the vacuum apply but instantly released vacuum. A 2nd wire ran to a 4th gear pressure switch in the valve body. So under light throttle the converter would lock in 2nd and 3rd gear with a warm engine with the throttle slightly open. Under acceleration it would unlock the converter and stay unlocked until the throttle was released enough to start pulling vacuum. In 4th gear the torque converter would lock and stay locked regardless of vacuum or engine temperature. I prefer the converter to lock in 2nd, 3rd and 4th gear when you are not under heavy acceleration as it provides a less slippage and better mpg in city driving.

1983 G20 Van, 350 TPI, Ported 906 Vortecs, Edelbrock 3817 Base, ASM oversize runners. Reed Custom Roller cam, 700r4, 12 bolt with 3.08 gears, Doug Thorley Tri-Y headers, true duals


Edited by 1983G20Van on 10-03-17 03:05 PM. Reason for edit: No reason given.

 
models916 
Valued Contributor
Posts: 4774

Age: 67
Loc: Addison, IL
Reg: 05-28-10
10-04-17 08:51 AM - Post#2709740    
    In response to 1983G20Van

You have to know what year. Use second pic from the left to ID the year.

https://images.search.yahoo.com/search/images?p=70...

https://www.ebay.com/sch/i.html?_from=R40&_trk...




 




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