700R4 build thread.

[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.