700R4 build thread.

[clinebarger]

Bad news, I pulled the valvetrain out of a 1986 4442 Valve Body.

You are missing the 1-2 LO Range Downshift Valve!

[psychodiagnostik]

Thanks man! I swear I don't remember seeing that valve when I took everything apart, I took it apart very slowly & laid the valves out as I took them out. But who knows, it could have rolled off the bench & disappeared. Is there anyway the transmission could have worked without it? At any rate, I'm going to look for a reman or salvage yard type 2 valve body with the one piece 1-2 sleeve, which as far as I can tell should have came on the car. The valve body disassembly photos on the corvette forums all show the one piece.

[clinebarger]

Originally Posted by psychodiagnostik

Thanks man! I swear I don't remember seeing that valve when I took everything apart, I took it apart very slowly & laid the valves out as I took them out. But who knows, it could have rolled off the bench & disappeared. Is there anyway the transmission could have worked without it? At any rate, I'm going to look for a reman or salvage yard type 2 valve body with the one piece 1-2 sleeve, which as far as I can tell should have came on the car. The valve body disassembly photos on the corvette forums all show the one piece.

I have never left the valve out, Or test drove a "Problem" unit that had the Valve missing. But one thing I can say is....Without it, The 1-2 TV Valve cannot "Relay" TV pressure to Oppose Governor pressure that is acting on the actual Shift Valve. Its only role except for acting as a Relay/Spacer is to keep Governor Pressure from Shifting the 1-2 Shift Valve from stroking while in Manual LO.

A few theories....
It would shift too 2nd as soon as you get rolling.
It would take off in 2nd gear.
Line pressure would flood the bore & the unit would burn clutches.

Nothing wrong with a Type-I Valve Body, Truth be told, They are better in High Performance/Heavy Duty applications. My gut feeling is that Valve is somewhere at your place...Some valves can roll 100', Ask me how I know.

I would like to know more about your unit, Aux. Valve Body? etc.

[psychodiagnostik]

Thanks! I'm glad to hear I just might be able to stick with my current earlier VB, if I can just score a salvage yard one or something to get that missing valve.

The unit does in fact have Aux.valve body, & it has three single prong pressure switches that hook up to the harness that just has three connectors. It has the block off plugs in the TCC hydraualic circuit. It does have the weak looking return spring in the throttle valve sleeve.

Also, the 1-2 accumulator valve looks like the one on the diagram for the 1988-1993 VB. Otherwise it looks like the 1982-1987 valve body diagrams in the ASTG manual.

Thanks again for the excellent write up & for taking a look at my parts!

[psychodiagnostik]

Also, I looked at my valves again, my 3-4 line up doesn't look like other pictures of an early 3-4 line up, my 3-4 throttle valve has smaller circumference lands, if that makes any sense.

[jamyers]

OK, any idea where I can find online Transgo instructions for their kits? Their website isn't exactly detailed in its descriptions, grr...

I've got an '84 version, and looking here and at Transgo's website I'm gathering that the following are the parts I can plan on collecting - the goal being a durable/reliable trans with a hydraulically-controlled TCC.

------------------------------------

Transgo 700-P separator plate
Transgo shift kit SK-700 (???)
Transgo 700-LU kit (???)

Dual pole brake switch
AC Delco 24241501 Teflon Tailshaft bushing
Th350 governor

Sonnax TV plunger valve kit #77966-94K (assuming wear on the existing parts)
Sonnax 77998-03K painless accumulator piston (do away with the pin / piston)
Sonnax 74926 accumulator spring

-------------------------------------





I'm thinking that the Transgo shift kit SK-700 is the way for me to go, as it
* Includes Transgo tv correction kit + good red line bias spring)
* Says "83-87 Valve body, Kit lets you make Torque Converter lockup-no wires or electrical needed" Can anybody confirm that I won't need the 700-LU kit separately?

Or would the Transgo 2-3 reprogramming kit have everything I need and more?

Also, Opinions on the need for the Sonnax parts? Haven't torn into the VB yet, but I'd rather have parts on hand than wait a week to get them.

Anything else I can do to the VB while I'm in there?

[clinebarger]

Originally Posted by psychodiagnostik

Also, I looked at my valves again, my 3-4 line up doesn't look like other pictures of an early 3-4 line up, my 3-4 throttle valve has smaller circumference lands, if that makes any sense.

1987 700R4's are this way, All the GearTrain Updates, Auxiliary Valve Body, But have a Type I Valve Body. Comparing Type I & Type II Valve Bodies is Futile! They are of a different "Porting" design.

However there are several hundred different Calibrations for both Type Valve Bodies that can vary year to year, model to model, engine to engine. If you like the shift timing you had....Leave it be.

Originally Posted by jamyers

OK, any idea where I can find online Transgo instructions for their kits? Their website isn't exactly detailed in its descriptions, grr...

I've got an '84 version, and looking here and at Transgo's website I'm gathering that the following are the parts I can plan on collecting - the goal being a durable/reliable trans with a hydraulically-controlled TCC.

------------------------------------

Transgo 700-P separator plate
Transgo shift kit SK-700 (???)
Transgo 700-LU kit (???)

Dual pole brake switch
AC Delco 24241501 Teflon Tailshaft bushing
Th350 governor

Sonnax TV plunger valve kit #77966-94K (assuming wear on the existing parts)
Sonnax 77998-03K painless accumulator piston (do away with the pin / piston)
Sonnax 74926 accumulator spring

-------------------------------------





I'm thinking that the Transgo shift kit SK-700 is the way for me to go, as it
* Includes Transgo tv correction kit + good red line bias spring)
* Says "83-87 Valve body, Kit lets you make Torque Converter lockup-no wires or electrical needed" Can anybody confirm that I won't need the 700-LU kit separately?

Or would the Transgo 2-3 reprogramming kit have everything I need and more?

Also, Opinions on the need for the Sonnax parts? Haven't torn into the VB yet, but I'd rather have parts on hand than wait a week to get them.

Anything else I can do to the VB while I'm in there?

Probably wont find full SK-700 instructions online, Though I can post them if need be.

The SK-700 comes with a Line Bias Booster spring, not the Red spring that comes with the SK-700JR, You are correct, The SK-700 is a nice kit for '82-'87 units.

The SK-700 allows use of the factory TCC valves in the Valve Body for hydraulic lock up.

Its late, Will update with more info.

[jamyers]

Originally Posted by clinebarger

...
Its late, Will update with more info.

THANKS! Man, I really appreciate your help.

I see you're in Ft. Worth, I'm just outside of Abilene, TX - if you ever get out this way let me know - love to buy you lunch and/or a beer!

[clinebarger]

Originally Posted by jamyers

THANKS! Man, I really appreciate your help.

I see you're in Ft. Worth, I'm just outside of Abilene, TX - if you ever get out this way let me know - love to buy you lunch and/or a beer!

Your welcome. Are you just doing a shift kit or a full rebuild?

I no longer recommend using a Sonnax Pinless Accumulator Piston in the 2nd Accumulator Housing with Trans-Go Springs, It breaks Accumulator Springs in some cases. You can use the Pinless piston in the 4th Accumulator.

SK-700G instructions....

[jamyers]

THANK YOU!

Originally Posted by clinebarger

Your welcome. Are you just doing a shift kit or a full rebuild?
...

I'm doing a shift kit and whatever else I can do without pulling the pump

[psychodiagnostik]

Originally Posted by clinebarger

Nothing wrong with a Type-I Valve Body, Truth be told, They are better in High Performance/Heavy Duty applications. My gut feeling is that Valve is somewhere at your place...Some valves can roll 100', Ask me how I know.

I would like to know more about your unit, Aux. Valve Body? etc.

I man I found that valve! I had torn my garage upside down, and finally just moved my whole workbench out, after searhcing under it with a flashlight. Somehow I missed it until I just moved the dang workbench out into the middle of the garage, & found it. So you were right! It was there all along, and must have fell out & went to the floor when I was dissasembling.

[matti]

Originally Posted by clinebarger

Time to Install the Valve Body.

Install the Manual Link Rod as shown in the picture below.

Hand tighten the 1-2 Accumulator Housing & Auxiliary Valve body bolts.

Remove the Z-Bolt alignment stud that is closest to the shifter Comb.....It gets in the way of installing the Valve Body.

You may need help holding the Valve Body over the Case to start the Manual Link Rod into the Manual Shift Valve.

Center the Valve Body over the remaining Z-Hole alignment Stud, Slowly lower the Valve Body onto the Separator Plate Gasket.

**NOTE, Before sitting the Valve Body all the way down...Make Sure no Checkball has fallen onto the Separator Plate, You can usually hear them drop, But still check**

Start the Z-Hole Valve Body Bolt First!

Install the Forward Accumulator Feed Pipe if equipped.

Start the rest of the Valve Body bolts, Be aware of the Brackets & Hold down locations in the Pic below.

I do the TV Actuator Assembly last along with removing the other Alignment stud

Hey, I am wondering if there should be a detent hole for fully round circle ended line bias valve (Picture I posted, I pointed it with red arrow). I am now setting up my own transmission and I am having a bit conflicting information. Transgo separator plate 700-P instruction does say nothing about that hole their plate is missing even though it should fit all model years between 82-93. Then Atra rebuild manual says it is necessary for the hole to be there for proper line bias valve operation. Have you faced this problem before ? I am wondering if I should drill this hole there or not ?

[clinebarger]

ATRA likes to make a Mountain out of Mole Hill on some of their bulletins.

The Round Line Bias works WITH or WITHOUT the Detent Hole.

The Slotted Line Bias is NOT compatible with a Separator with a Detent Hole.

That is why Trans Go makes no mention of it, But I have to say.........Good attention to detail to notice!

[matti]

Originally Posted by clinebarger

ATRA likes to make a Mountain out of Mole Hill on some of their bulletins.

The Round Line Bias works WITH or WITHOUT the Detent Hole.

The Slotted Line Bias is NOT compatible with a Separator with a Detent Hole.

That is why Trans Go makes no mention of it, But I have to say.........Good attention to detail to notice!

Thanks man for fast answer! that is just what I wanted to hear. I was wondering if it will make a fluid pocket there and that way block some valve operations. It is not always good for me to be a mechanical engineer, always aiming attention to small things .

Other thing I was wondering. I tested my combo now and it works pretty well. However I think shift points take place at way too high rpms now. I assembled there fairbanks 0.500 megavalve and low/rev boost valve, have you experience if these two valves will require some sort of valvebody calibration to take shift points down they used to be? I am using the same diesel governor that was installed there before pump meltdown.

[clinebarger]

Larger Ratio Boost Valves do not alter Shift Timing, Incorrectly set TV Cable or TV Valve malfunctions are things I would look at first.

[joeyv69ragtop]

Originally Posted by psychodiagnostik

I man I found that valve! I had torn my garage upside down, and finally just moved my whole workbench out, after searhcing under it with a flashlight. Somehow I missed it until I just moved the dang workbench out into the middle of the garage, & found it. So you were right! It was there all along, and must have fell out & went to the floor when I was dissasembling.

Man I hope I have the same luck. I got my case, and a few other parts back from the trans shop that was installing bushings and washing my case in the jet wash. I'm putting everything back together and I realized I lost the nut the holds the detent lever to the shift shaft! Looking back I know just when I lost it, too. I had a bunch of parts in the pan and it tipped over. Thought I got everything but I guess i was wrong lol.

[joeyv69ragtop]

I've got a couple of questions RE my rebuild. Maybe some of you have experienced the same thing.
1. I have the transgo separator plate and since I have the auxiliary valve body I need to use those aluminum slugs to block two of the holes. Well, after the first plug shot across the garage into oblivion after I hit it with a hammer, I used a punch to seat the second one. Now that I still have to plug one hole and I don't have another aluminum plug, does you have any thoughts for what else I could use to plug the hole?

2. Ive got my eye on a used shift shaft with the nut on ebay but I'm wondering if a regular grade 5 nut would suffice instead of the original black nut with the grooves cut in it.

any thoughts appreciated.

Thanks!

[matti]

Originally Posted by joeyv69ragtop

I've got a couple of questions RE my rebuild. Maybe some of you have experienced the same thing.
1. I have the transgo separator plate and since I have the auxiliary valve body I need to use those aluminum slugs to block two of the holes. Well, after the first plug shot across the garage into oblivion after I hit it with a hammer, I used a punch to seat the second one. Now that I still have to plug one hole and I don't have another aluminum plug, does you have any thoughts for what else I could use to plug the hole?

2. Ive got my eye on a used shift shaft with the nut on ebay but I'm wondering if a regular grade 5 nut would suffice instead of the original black nut with the grooves cut in it.

any thoughts appreciated.

Thanks!

Hey, I had to install both of these slugs according to transgo instructions. Well what happened few weeks after .. The shift lever jammed in way that I was not able to put it in manual low or 2. Drive zones, reverse, park and neutral worked fine. I cleaned the valvebody and assembled it back. After I had installed it back I found one of these two slugs swimming at bottom of my oil pan. I had to test it and it worked fine, I did not notice any changes in shift behavior. I will of course put it back sooner or later just in case, or I will just buy another separator plate and hope better luck.

So my recommendation to you; make sure you hit it hard and right way there so you don't have to take it apart again. I think I did and yet it did not want to stay in its place.

Does some of you happen to know if these slugs have great importance for proper working of this transmission? Or what these slugs actually do ? I am wondering if I will destroy my transmission driving without one slug, and I don't know yet which one it is.

[clinebarger]

If both you guys have a Type II Valve Body along with a Auxiliary Valve Body, BOTH holes need to be plugged per Trans-Go's instructions.

[joeyv69ragtop]

Originally Posted by clinebarger

If both you guys have a Type II Valve Body along with a Auxiliary Valve Body, BOTH holes need to be plugged per Trans-Go's instructions.

I've got an aux valve body but my primary valve body has the ports for the dummy slugs, which have since been replaced with the transgo hydraulic lockup kit so I can eliminate the wiring. I still haven;t finished assembling the trans because I haven't found a suitable replacement for the slug I lost. The second slug, which I thought was lost, was actually glued to my separater plate with trans fluid and I found it when I was drilling the holes larger as per transgo instructions. Instead of hitting it with a hammer I used a drift punch and I was able to seat the slug. Trying to make a new slug from a small diameter aluminum welding rod but it's not ready yet.

[bry593]

Recently picked up a '92 700R4 coded for an R truck or G Van.

Upon teardown, I discovered the solenoid to be plugged with a ball and the wire harness missing. Checking the pump, I did not find a non-l/u valve.

Removing the valve body, I found it has a complete TCC valve kit and this does not match a '92 transmission.

There casting code on the valve body is 4256. The body has 2 holes retaining the 1-2 shift valve bushings. It also has a "B" stamped into the casting. Upon teardown, I found it has a two piece, lo-range downshift valve as you show in the pic above^

My question is whether this valve body really is compatible with my '92 case, seperator plate "EA" and auxillary valvebody. It is difficult to say whether the previous builder knew what they were doing as I got it as a "rebuild gone bad". The 3/4 stack was completely smoked, but I also found the 3/4 piston seal lip torn about 1/2".

Any insight is appreciated!

[bry593]

I have one more question. In your rebuild writeup, you said not to mix and match steels from the early to late 700r4 reverse input. I found my reverse input had a wave instead of a belleville and the clutch clearance excessive. I ended up re-using the waveplate and adding 2 extra thick steels along with 3 standard thickness turbulators to get the correct clearance. Note it does have the later aluminum piston as opposed to the early steel piston. Will this cause any issues?

Another oddity about this trans is that it has what ATSG lists as the '93 low carrier support (.250" thk) along with the 725 low/reverse piston. This didn't seem to cause any issues with my stack height, and I reassembled with a 550 piston per recommendation.

By the way, my new 3/4 stack is M30 (6x .106) and my sunshell is M32 (late reaction shaft and thrust bearing).

This is all slated to be used in a '70 2-dr Caprice with a 413 CID small block and 3.73 gears.

[clinebarger]

Originally Posted by bry593

Recently picked up a '92 700R4 coded for an R truck or G Van.

Upon teardown, I discovered the solenoid to be plugged with a ball and the wire harness missing. Checking the pump, I did not find a non-l/u valve.

Removing the valve body, I found it has a complete TCC valve kit and this does not match a '92 transmission.

There casting code on the valve body is 4256. The body has 2 holes retaining the 1-2 shift valve bushings. It also has a "B" stamped into the casting. Upon teardown, I found it has a two piece, lo-range downshift valve as you show in the pic above^

My question is whether this valve body really is compatible with my '92 case, seperator plate "EA" and auxillary valvebody. It is difficult to say whether the previous builder knew what they were doing as I got it as a "rebuild gone bad". The 3/4 stack was completely smoked, but I also found the 3/4 piston seal lip torn about 1/2".

Any insight is appreciated!

The solenoid is plugged so the TCC can operate without power to the TCC Solenoid, Pure laziness on the part of the builder/installer, Get a new TCC Solenoid & wire it to a Dual Pole Brake Switch like I stated earlier in this thread when using a Converter Shift Valve in the Valve Body.

A Type-I Valve body is 100% compatible with a '92 case, But you need a different Separator plate (EA is a '92 Plate code) & INSTALL Checkball #9.
A Trans-Go 700-P plate is the easiest way to accomplish this, You will only plug 1 hole (Because you have Aux. Valve Body) DO NOT install #5 Checkball in the Valve Body "Bath-Tub"

Plate differences....Note the 2 round holes (Detent & Lo) on a Type I Plate, And 1 Square hole (Detent) on a Type II Plate, GM made it square so even if #9 Checkball is installed...It will not seal. If it had a Round Detent Hole, You could just drill a new "Lo" hole....But that is not the case.

[bry593]

Thanks Chris. All I've got is the blue ATSG book, and I could not conclusively tell what all needed to happen to ensure this Frankenstein would come alive.

Will be ordering the 700-p along with a few other things I lacked the foresight to buy the first time. I swear, I've ordered four separate times and still need more parts. Been working on this for three weeks, mostly waiting on parts.

So, I guess I'm okay using the wave in the reverse input? Can't see why it would be a problem so long as clearance checks out.

Do you think the M30 3/4 stack will be okay behind my 6.8 liter motor? It's out of breath by 4500rpm but makes gobs of torque down low. I've got to order more parts and could pick up another high energy fiber and some .076 steels....

I installed a Trans-go 700 sk-jr. I have a question about Gil's 1/2 accumulator spring set up. He has springs on both sides of the piston, presumably to reduce overall piston stroke to bottom. Is this a good idea or should I use a purple sonnax along with stock inner? I plan to disable 3/4 accumulator by reversing spring and piston.

I will be installing a vette servo along with a sonnax .471 boost and pressure spring. I'm looking for driver quality shifts at driver throttle, and firm shifts wide open.

By the way, and I'll probably get roasted for this but.... My input shaft was leaking at the drum. I heated assembly in the oven and pressed the shaft out. Seeing that there was only about 3/16 engagement to the top of the 3/4 drum feed hole, I knew green loctite wasn't an option. So, I Scotchbrited the drum and shaft and then reheated drum to 400F. Pulled out of oven, coated shaft and drum with acid flux and literally dropped the shaft into the drum. I then used high strength solder with a 480F flow to bond the components. After peening all the piston and drum check balls with a drift, I've got 100℅ sealing at 40psi. Time will tell how well it holds up, but it's got to be better than green loctite.

[clinebarger]

You may have a harsh Reverse engagement using a wave plate in lieu of a Belleville, Especially if your R/I Drum & Pump Stator both have large feed holes....It can get nasty!

Use 7 High Energy Frictions & 6 .077" Steels along with GM# 8685044 Apply Plate & GM# 24212460 Backing Plate. The extra friction will help handle the torque.
The Apply & Backing plate are the latest 4L60E designs & are really stiff to reduce flexing.

The 2nd Accumulator springs in the Younger kit work very well to smooth out the 1-2 shift, Drill the 2nd feed hole .076"-.086". Watch your Band clearance! I like about .060".

With the low rpm torque your going to produce, A .500" TV Boost Valve would be a good idea, Sonnax# 700R4-LB1....Use the supplied PR Spring in place of the Green TG PR Spring.

Pump Rings & a Higher Rate Primer Spring is also recommended Trans-Go# 700-PHK.

I'm not here to roast anyone, The best I can do is advice! While what you did is unconventional & I have a serious concern that Solder would flow into a feed hole & restrict it, That air testing will not detect....I hope it works out for you!

What I do in a situation like this.... I buy a New 300mm 4L60E Input Drum from GM ($175) Press the 300mm shaft out, Press the 298mm shaft in with retaining compound.