Hi!

I have recently rebuilt my 1992 TH700R4 transmission which had a cracked input drum and now got a Stage4 drum from FinishLineTransmissions along with other nice parts, such as a 2400 stall converter.

I have bought a TransGo Stage2 Shiftkit ( Noyoyo Kit ) too and misplaced some of the springs, so that my transmission shifted a little bit nervous.

So I tried again, and now I'm totally confused with the springs. And as I looked closer, the bore of the TV valve is very bad, think i should not re-use my valvebody any more, the inner walls don't look really smooth any more and you need to be really strong to get that tv-plunger out of the bore (no, i didn't forget to remove the rollpins )

And now to my question :
A friend of mine has a broken 1987 th700 transmission. Can I fit it's Valvebody into my 92' unit?
My VB has Casting #63 ; his one has #47.

I don't see big differences , just the existing "dummy plug" and an additional "ground" on the other side of the VB.

Can anyone answer that question?
It would probably take too long to get a new 88-93 valvebody from the usa to germany, and i'm in a bit of a hurry.


thanks in advance

alex

 

Do you have the matching separator plate to go with this 1987 valve body? If the separator plate has the ID letter code that starts with an "A" , it is a "first" design valve body, (your valve body from the 1992 is a "second" design) you must use the separator plate and this valve together. If the separator plate has the ID letter code that starts with a "B", then you can use the valve body with your 1992 separator plate. Use your line bias valve from the 1992 valve body into the 1987, if it is a "second design" (separator plate has the ID letter code that starts with an "B") valve body. This way there will be no line rise problems with this valve.

 

Thanks alot.
Sounds like good news for me

I have the separator plate from the 87 unit.
My 92' unit's s.p. has "EM" as I.D.

And the line bias valves... i compared them some days ago (haven't found the correct spring from my shift kit , and the installation instructions are really confusing... thanks to "mr shift" ). The older lb-valve is smaller than the newer one, but i think it was only the side where the spring sits.

I'll now check all springs for length, diameter etc.


thanks again
alex

 

The line bias valve will measure the same in diameter, but the end where the spring sits against it, is sometimes different. Some have a flat spot on them, the other is round. With the TransGo Shift kit use the RED spring here, instead of the blue one. If you need help with the instructions let me know?

 

Oh, my fault. I meant the 3-2 valve which is slightly smaller in the 87' valvebody. I haven't compared the line bias valves yet.

tomorrow or on sunday i'll begin to disassemble both vb's and to measure all of the springs. hopefully i find all necessary springs from the transgo kit, but i think there will be missing some of them.



Edit:

Now i have a terrible headache
I checked all the springs according to the pdf sheet for the 87' valvebody which i found @ transgo's website.
Problem: I found only few matching springs:

- TV Spring (was pretty easy *g*)
- (maybe) Line Bias valve
- TV limit valve
- MTV down
- 3-4 sequnce/relais spring

And now i'm sitting in front of 36 (!) unused springs. some of them are from my 92' VB , most of them came with the shiftkit which was way too expensive [round ~$200 [160€] , especially because of the crappy instructions. maybe mr.shift was on mushrooms when he wrote those instructions.

 

*bump*

After a cup of coffee and some cigarettes, my brain worked again

I've found almost all of the matching springs.

2 Springs are missing, and i have still many springs lying in front of me.

1. Accumulator Bushing/Valve
- Instructions say:
:: Accm code A and B ; 2nd piston 553&554 use BROWN spring
:: All other Accm codes and piston 553&554 use ORANGE spring
:: All accm codes with 093 ir 95-1 piston use BLACK spring

My original spring is: [ 1.346"x 0.26" x .020" ]

2. 3/2 Control valve

Should be a Blue spring. The original has this measurements
[ 1.010" x 0.30" x .037" ].

The blue springs I found have following measurements:
[ 1.410" x 0.30" x .034" ]
and
[ 1.050" x 0.32" x .024" ]
and
[ 1.098" x 0.24" x .035" ]

There is a pink spring which is very similar to the original one:

[ 1.014" x 0.32" x .041" ]

and another blue one:

[ 1.204" x 0.32" x .041" ]




@ Pro Built Automatics: Do you have the right measurements for those 2 (3/4) springs?

 

This one is the 3-2 spring from TransGo,
blue one: [ 1.204" x 0.32" x .041" ]
The other pink and blue springs are for the line bias valve. You should have a red spring that is similar to the pink and blue springs for the line bias, if you have this use it for the line bias, if not the blue will have to do.
With the Corvette servo, use the black spring in the 2nd accumulator valve, if it has the "A" or "B" ID on the bushing.
For Heavy Duty use, drill "A" (3rd gear) to .135". "E" (4th gear) to .135". "F" to .093". If you want a quicker 3-2 downshift, drill hole "C" to .135" and leave the spring off of the 3-2 valve all together.
Which 3-4 springs are you talking about? Are you talking about the 3-4 shift valve? If you are, what year are you working on ? And is it the 1st or 2nd design valve body?

 

All springs are in



Hope to upload a video in 1-2 days.

greez
Alex



EDIT: Everything worked out so far. My GTA is back on the road again.
Just one single problem remaining: Shiftpoints are very low, about 4000rpm @wot , with the 87' governor installed and maximum tv setup. 1-2 clicks away from maximum tv, the shift points are at about 3800rpm. No "double downshift" possible in with this setup.


Then I used my 92' governor and the shiftpoints are too high, at about 5800-6200rpm , very nervous downshifting especially at wot.
don't want to have more than 5000rpm, this would be high enough i think. hope i can cure this with using other weighs&or springs in my governor.

 

*and another bump*

Have some problems with my shift points.
With the stock red/blue springs in my governor, my tranny shifts to second with minimum throttle at about 2800rpm, and at wot at about 6000rpm.

Changed the red spring to a blue one, 1-2 shift rpm went down to about 2500rpm , wot ~5800 ; 2-3 shift at ~5000rpm

Another thing I experienced: Sometimes when accellerating at ~1/3 throttle in 1st gear, the rpm's rise but it doesn't feel much like accellating. The next time, everything feels ok. Seems that the "coast down mode" will not disengage until about 2500rpm when turning back to "accelleration mode". Maybe normal with my 2200-2800 stall converter, but I don't know.

VIDEO HERE --> http://www.youtube.com/watch?v=f5fvRsF_j6I

greez
Alex