Putting a 1987 700R4 in my 1982 GMC 4x4...

Awhile back, I posted that the Internal Reaction (Ring) Gear shattered in my 1982 GMC 2500 4x4 truck. Here are the links to my previous posts.

http://67-72chevytrucks.com/vboard/...ad.php?t=217634
http://www.hotrodders.com/forum/int...0r4-103421.html

I decided to take Jonboy's advice and purchase a SRTA (Service Remanufactured Transmission Assemby) 700R4 from my local GM dealership. The price was right -- a little over $1600 plus labor -- and they come with a 3 year, 50K mile warranty. Sounds good to me. How could I go wrong?

Well, that didn't work out. I visited two GM dealerships. GM doesn't offer a SRTA 700R4 for the 1982 thru 1986 model years -- only for 1987 and newer. GM won't honor their warranty on a 1987 SRTA installed in a 1982.

I asked them to go ahead and install it without warranty. Still, they declined to install it. I believe it is because of the differences in the vacuum/electronic mechanism for the Torque Convertor Lock-up between 1982 and 1987 model years.

In case anyone is interested, GM offers a performance grade AL60-E transmission for older model years, including 4x4 trucks.
p/n 19156259, trans, $2,174.00
p/n 12497316, (computer) module, $1,284.00
They even offer an AL85-E for slightly more money.

This leaves me with two options:
1) Purchase a crate 700R4 from a rebuilder.
2) Purchase a used 700R4 from a salvage yard 700R4 and have it rebuilt locally.

Question #1
Many shops here in Indiana have strongly recommended that I stay with a 1982-1986 700R4. Everything that I've read says otherwise -- I should upgrade to 1987 or newer. Should I continue searching for a shop that is willing to install a 1987 700R4 in my 1982 vehicle?

Question #2
How does the factory mechanism to lock-up the torque convertor in my 1982 vehicle actually work? I see some vacuum hoses. I see a thermo-valve. I see a solenoid with two wires. I think that I see a one-wire connector on my 1982 torque convertor. I can't find anything to un-lock the TC using the brake light circuit.

Question #3
Will the 1982 factory mechanism work properly on 1987 TC? I believe that the one-wire solenoid on 1982 grounds internally to transmission case. I believe that the two-wire solenoid on 1987 allows me to place an override switch on the external ground wire.

Question #4
I am aware of...
TCI AUTO TCI-376600 Torque Converter Lockup Kit
http://www.tciauto.com/Products/GM/gm_2004r.asp
http://store.summitracing.com/partd...rt=TCI%2D376600
http://www.jegs.com/webapp/wcs/stor...10002_748599_-1

B&M TC Lock-up Kit
http://www.bmracing.com/
http://store.summitracing.com/partd...art=BMM%2D70244

Painless Wiring TC Lock-up Kit - 764-60109
http://www.jegs.com/webapp/wcs/stor...747219_-1_10733

What are the advantages of using these kits over my 1982 factory mechanism?


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This should not be difficult for any decent trans shop,if you do not have one in your area contact RC Auto Transmission Service,Aledo Il.I used to own this shop and we did these conversions all the time.The early 700's are weak and I agree they should not be rebuilt,'87 up are much better and can easily be made to fit your truck.This job should be less than $2000. including the R&R.Hope this helps,good luck

before you search any where else go to this site. 700r4l60e.com. i think you'll be amazed at the info.by the way when gm brought out the t400 and the t350 they were killer from day one.gm built transmissions to handle power.then when they did'nt produce engines a sick squirrel could out run they brought out the garbage 700r4.it took them 5 years to just get the thing to handle some power.go to pro builts site.these things can be built and at an affordable price.no i have not purchased myself yet but thats about to change

I am surprised to see you are still grappling with this decision, although I do understand your caution.

I would buy a 1987 core unit, find a shop in your area that can build it to fit your requirements,you have done a ton of research,so you know what you need,and have them install it.

A good shop will know how to deal with your lockup concerns, the TCI kit -376600, would not be a bad way to alleviate the lockup situation[82-87].

You may or may not have a low vacuum switch in your system[used to disengage lockup at closed and wide open throttle].

You may have a vacuum delay valve [found between the low vacuum switch and carburetor], this is used to help prevent the back and forth,engagement-disengagement busy lockup, occuring with slight throttle changes.

The thermal vacuum valve will not allow vacuum to reach the vacuum switch, until the engine is warmed up.

I hope this information helps you,we just installed a 1988 700R4 in a 1970 Pontiac Le Mans. We used the TCI lockup kit,with no problems. Dana

Update to...
http://www.hotrodders.com/forum/put...4x4-107964.html
http://67-72chevytrucks.com/vboard/...ad.php?t=225385



Using local phone directory (yellow pages), I spoke with several parts suppliers that specialize in transmissions. They recommended several local shops that specialize in 700R4.

I searched for a neighborhood member of Automatic Transmission Rebuilders Assoc (ATRA)
http://www.atra.com/source/amembers...?searchtype=reb
http://www.atraonline.com/source/am...?searchtype=reb

--UPDATE--
http://www.hotrodders.com/forum/put...4x4-107964.html
http://67-72chevytrucks.com/vboard/...ad.php?t=225385



The centerpiece is the TC Clutch Lock-Up Solenoid. The mechanism that controls it uses vacuum, electronics, and hydraulics.

To lock-up the TC Clutch, the solenoid requires 12V power and hydraulic fluid pressure.

The Electronics Side.

a) Switched 12V Power. 12V source from either the Accessory or Ignition circuit.

b) Normally Open Brake Switch. There are two brake switches. When the brake pedal is depressed, the normally-closed brake switch turns-on 12V power for the brake lights and the normally-open brake switch turns-off 12V power for the TCC Solenoid. This switch functions in a similar manner as a cruise-control switch. This is a fail-safe mechanism, if the hydraulics side should stop working correctly. Otherwise, the engine would die while coming to a stop because the TC stayed locked-up.

c) Vacuum Switch.
1. Vacuum source is from the intake manifold.
2. Thermal-valve allows vaccum after engine reaches operating temperature.
3. Vacuum regulatory valve (GM-140206691) smoothes out spikes in vacuum.
4. Vacuum switch turns-off 12V power when vacuum drops below predetermined psi. My guess is somewhere between 6-9 psi. This un-locks the TC whenever the engine is under load conditions - e.g. wide-open-throttle or climbing a hill.

d) TC Clutch Lock-Up Solenoid. When open, this solenoid valve allows fluid under pressure to pass thru to Torque Convertor.

e) Ground side of solenoid, normally open 4th gear pressure switch. I do not know for a fact, but there may be (or may not be) a ground switch which turns-on when fluid is under pressure to activate 4th gear. There may (or may not) be another similar ground switch for 3rd gear.

f) Ground is done inside of transmission.

Things that changed when carburator was replaced with throttle body injection (TBI) setup...

a) Vaccum switch and corresponding vacuum hoses were removed as engine load conditions - e.g. wide-open-throttle, climbing a hill, etc can now be calculated by computer using the manifold absolute pressure (MAP) sensor.

b) TC Clutch Lock-up Solenoid changed from one-wire to two-wire.

c) Electronic Connector increased to four pins.
PIN-A - 12V power
PIN-B - ECU input signal, 4th gear in use
PIN-C - Unknown to me
PIN-D - TC Clutch Lock-Up ground

d) ECU now has complete control of TC Clutch Lock-up. It closes the ground side of TCC Lock-up Solenoid circuit, whenever it wishes the TC to lock-up.



The Hydraulics Side.

It may be best just for you to ask for the hydraulics circuit diagram for TCC Lock-up from a dealership service manual. In my understanding, in the valve body...

a) Throttle Valve. The Throttle Valve (T.V.) cable is adjusted at carburator to determine throttle position.

b) Speed Governor. A gear on the transmission output shaft is used to determine vehicle speed.

c) TC Lock-up Valve. There is a battle of fluid pressure between Throttle Valve and Speed Governor. Whenever the Speed Governor wins the battle, the TC Lock-Up Valve allows fluid pressure to flow to the TC Clutch Lock-up Solenoid.

Things that changed when carburator was replaced with throttle body injection (TBI) setup...

In the valve body, the hydraulic circuit that regulated flow of fluid to the TC Clutch Lock-up Solenoid was plugged. The TC Clutch Lock-up Solenoid now receives constant continuous fluid pressure. If the TC Clutch Lock-up Solenoid electric circuit is grounded and the ECU removed, then the TC Clutch will lock-up in 2nd, 3rd, and 4th gears. It will not lock-up in first gear because the hydraulic circuit in the valve body does not allow fluid to pressurize until 2nd gear is reached.

--UPDATE--
http://www.hotrodders.com/forum/put...4x4-107964.html
http://67-72chevytrucks.com/vboard/...ad.php?t=225385



It all depends upon the hydraulics, i.e. which valve body was used when the 1987 donor transmission was built. Valve bodies were improved, even in the middle of a model year. Of course, the 1982-1986 valve bodies will have the TC Lock-up hydraulic circuit. Some 1987-1990 valve bodies still have the circuit, just different valves to keep circuit open. Some 1987-1990 valve bodies still have the circuit, just plugged to keep circuit open. Some 1997-1990 and all 1991-1992 valve bodies, the circuit was removed all together.

This is why companies developed TC Clutch Lock-up Kits. The instructions for the B&M TC Lock-up Kit has the most very useful information...
http://store.summitracing.com/instr...m%2D70244%2Epdf

--UPDATE--
http://www.hotrodders.com/forum/put...4x4-107964.html
http://67-72chevytrucks.com/vboard/...ad.php?t=225385



Search for various kits here...
http://store.summitracing.com/egnse...+115+4294903956


TCI AUTO TCI-376600 TC Clutch Lockup Kit Instructions
http://www.tciauto.com/Products/Ins...376600_inst.htm

Does NOT have normally-open brake switch.
Does NOT have Vacuum Thermal Valve.
Does NOT have Vacuum Regulatory Valve.
Does have Vacuum Switch.
Replace TCC Lock-up Solenoid wiring harness inside of transmission.
Splice into existing TCC Lock-up Solenoid (two-wire).
Replace 4th-gear pressure switch (two-wire).

TCC Lock-up occurs when...
1. Vacuum is greater than 9 psi.
2. Transmission is running in 4th gear only.

Kit has manual lock-up switch in order to lock-up while running in 3rd gear when towing a trailer. However, driver must remember to turn off switch while vehicle comes to a stop.


Painless Wiring 764-60109 TC Clutch Lock-up Kit Instructions
http://store.summitracing.com/instr...f%2D60109%2Epdf

Does have normally-open brake switch.
Does NOT have Vacuum Thermal Valve.
Does NOT have Vacuum Regulatory Valve.
Does have Vacuum Switch.
Replace TCC Lock-up Solenoid wiring harness inside of transmission.
Replace TCC Lock-up Solenoid (two-wire) -- no splicing
Replace 4th-gear pressure switch (two-wire).

TCC Lock-up occurs when...
1. Vacuum is greater than unknown psi.
2. Transmission is running in 4th gear only.


JET Performance JET-700211 TC Clutch Lock-up Kit Instructions
http://<br /> http://store.summitr...15&autoview=sku
http://www.jetchip.com/products.asp?pid=14475


Does NOT have normally-open brake switch.
Does NOT have Vacuum Thermal Valve.
Does NOT have Vacuum Regulatory Valve.
Does have Vacuum Switch.
Replace TCC Lock-up Solenoid.

TCC Lock-up occurs when...
1. Vacuum is greater than unknown psi.


B&M 70244 TC Clutch Lock-up Kit Instructions
http://store.summitracing.com/instr...m%2D70244%2Epdf

B&M takes a different approach. Rather than restricting the TC lock-up to just 4th gear, B&M replaces the internal hydraulic functions with a speed pulse generator.

Does NOT have normally-open brake switch.
Does NOT have Vacuum Thermal Valve.
Does NOT have Vacuum Regulatory Valve.
Does NOT have Vacuum Switch.
Does have Electronic Black Box.
Does have Speed Pulse Generator.
Does have adapter for speedometer cable.

TCC Lock-up occurs when...
1. Vehicle is traveling above adjustable predetermined m.p.h.
.. Kit suggests somewhere between 30 and 40 m.p.h.

--UPDATE--
http://www.hotrodders.com/forum/put...4x4-107964.html
http://67-72chevytrucks.com/vboard/...ad.php?t=225385

What did I decide to do?

I am keeping the factory OEM electronics...
a. Replacing OEM vacuum switch with adjustable aftermarket vacuum switch.
b. Performing a test with volt-meter to insure electronics are working properly.
c. Adding an indicator-on light to dash using ground side of TCC Lock-up solenoid.

I am keeping the factory OEM vacuum mechanism...
a. Replacing all rubber vacuum hoses with silicon hoses.
b. Installing Vacuum Regulatory Valve (GM-140206691)
c. Performing a test with vacuum gauge to insure vacuum mechanism is working properly.

Since I do NOT wish to modify hydraulic circuit in valve body and
since I do NOT wish to modify internal wiring harness,
I am installing B&M 70244 TC Clutch Lock-up Kit to perform the function that was previously performed by TCC Lock-up Solenoid circuit in valve body.

Other folks may wish to use circa 1987-1988 valve body. Others may wish to modify 1987-1988 valve body to use larger 1991-1992 valves. I am going to insure that TC Clutch will lock-up in 2nd, 3rd, and 4th gears and then install B&M kit to restrict lock-up to vehicle speeds above 40 m.p.h.

WOW!!! That bit of information took some time to research! If I ever need to find a needle in a haystack, Robert, I will contact you first.

This info should prove to be quite usefull to anyone faced with a similar challange.

Please let us know when your project is complete. Dana

Congrats on the research.


I hope you have the proper inline vacuum delay module for the vacuum switch in the 12 volt feed circuit to the trans.

OR perhaps your switch has a built in vacuum drop delay so the converter clutch does not bounce back and forth from lock-up to unlocked.

__________________
At the Bonneville Salt Flats, first gear is known as 130 mph.

Spank My Marketer

Also, the shop rebuilding my transmission decided to order your company's custom-designed 4-pinion rear planetaries.

http://www.briscoetrans.com/pdf/torque_bully2.pdf

Is this vacuum delay module GM-140206691? My 1982 GMC has what looks like a blue plastic check-valve (smaller than a quarter) about 2 inches to the right of the vacuum switch.

Anyway, I'll double-check and then check again for a third time.