700R4 build thread.

[psychodiagnostik]

AWESOME thread, I found this thread doing google searches about the 700r4 I'm re building for my '93 Corvette.

I've followed along but now I'm stumped, could anybody provide any insight? So I'm second owner of the car, car worked fine a few years until I lost reverse, & the teardown shows lo-reverse clutches disentegrating (fluid was trashy too). The trans looks like a GM rebuild, V /MD8 case, with the code ground off and a sticker on the bellhousing.

Valve body is a 4442, aluminum slugs in the hydraulic TCC channel. The thing that has me stumped is that instead of a one piece 1-2 throttle valve sleeve and valves I have the two piece, 1-2 sleeve and "lo range control sleeve" like an older valve body. Also the really weird part is the little 1-2 "lo range control" valve is missing. I've searched all over, thinking maybe it fell out when I dissasembled the valves but this seems unlikely & I didn't find it under or around my workbench.

Is this a normal configuration? Should I just get a new later series re-man valve body?
thanks!

[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

[jamyers]

Originally Posted by clinebarger

...
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.
...

I'm betting this one had a trans-go spring between the 2nd Acc piston and the separator plate - given the pic below from when I opened it up back in August.

Your above comment didn't soak into my head until after I'd driven out the 2nd Accumulator pin and staked the ball from the Sonnax Pinless kit into the housing. I didn't think it would be a good idea to try and go back, so I went ahead with the Sonnax Pinless piston and the original unbroken spring, as per Sonnax's '94-Later instructions (spring in the Accumulator body, then Piston with dome toward the separator plate). Do you see any issues with that setup?

FWIW, the Trans-Go springs are a tight fit into that Sonnax piston, no wonder they can break.

[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]

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.

[bry593]

Good advice. I have ordered the .088" Belleville, .077 plates and an additional friction.

One last question, during disassembly of this "rebuild gone bad", I noticed the servo return spring was missing. I am having a very difficult time trying to find a replacement. This is the spring that goes between the case and the servo assembly. No one seems to carry this, but all offer a "servo return spring" which turns out to be the little spring that comes in the seal kit. What part number should I be looking for? Why would a trans builder leave this spring out?

[clinebarger]

It needs the Servo return spring, Some builders omit, And some shift kits call for the omission. It doesn't do any good to leave it out!

You should be able to find a used one easy.....As 4L60E's use the same spring.

[bry593]

Not having any luck with the spring as of yet.

Other news: My fluid pump housing was badly gouged on one half and also the shaft had some wear at the converter bushings. I ordered a remanufactured 700r4 pump from Transmission Depot, but it is actually rebuilt by Dacco.

Upon opening the Dacco box, the first thing I notice is that the stator splines are worn half-way through. This is not an exageration. What should I do? Should I risk changing the stator shaft myself? I would think not, since TransDepot brags about how they resurface the pump perpendicular within .001" of the housing. Besides, if I open it up and find that Dacco has performed additional half-assed work, a return might be rejected.

Can anyone recommend a pump resurfacing company that will machine or grind my original housing?

[bry593]

Transmission Depot is providing a full refund (less my return shipping), so I'm only out $20 and a another week of downtime.

I found a place called Built Right Transmissions in Shreveport, LA that will remachine the pump faces and cavities for $55. They will also install a new stator and rotor group for a fair price. Total cost should be no more than the Dacco junk.

[Keckdl]

I am getting ready to do a full rebuild my transmission and was thinking about putting in a TCI constant pressure valvebody, what is your opinion on these? I cannot find any reliable info on using them or true benefit. Do you have any insight or experience with these?

Thanks,
Dan

[clinebarger]

Originally Posted by Keckdl

I am getting ready to do a full rebuild my transmission and was thinking about putting in a TCI constant pressure valvebody, what is your opinion on these? I cannot find any reliable info on using them or true benefit. Do you have any insight or experience with these?

Thanks,
Dan

The Front Pump will wear out prematurely form operating at near 100% Duty Cycle all the time, 700R4/4L60E/2004R Variable Displacement Vane Style Pumps have several moving parts compared to a TH350/TH400/4L80E Fixed Displacement Gear Style Pump.

A Billet Pump Rotor is absolutely necessary with Constant Pressure, The stock cast pump rotor is not designed for a 100% Duty Cycle.
http://www.ckperformance.com/View/70...PUMP-ROTOR-KIT

The trans will shift hard under light throttle, This beats up the Splines & Hard Parts in general........It is really bad on Chain Style Transfer Cases!

The only good a Constant Pressure VB will do is allow you too adjust the TV Cable for Shift Timing.....Incorrect TV adjustment will not burn frictions with this VB.

Fine tuning a 700R4 to Upshift/Downshift exactly when you want makes Carb Tuning look easy.