Transgo and 700R4 woes

[Toehead]

I'e been having problems with my 700 for almost six months. It started last november. I normally do all my own work, but I was away at school, so I decided to let my mechanic install my 700R4 2&3 transgo kit. He installed the kit, took it for a test drive. Worked well for about a mile, then stopped shifting. Turns out the holes in the seperator plate were too large for the supplied plugs, so he tried to jb weld the holes shut, which of course didnt work. I get a new seperator plate and use steel rod to plug the holes on a weekend I was home. I give this to him. He installs it, shifts are better, but still no holding power. He takes it apart again, cleans and reassembles. Shifts improve more.

It turns out that he couldnt find the boost valve bore. On a weekend i'm home, I install a new .500 boost valve, and grind the land as per direction in the transgo kit. The shifts are now pretty decent, but the 1-2 shift is sloppy and strange.

Last week, he calls transgo with a pressure gauge, and they tell him that he needs to put in a vette servo. (I had previously had one that I was waiting for me to have some free time)

We put that in, and here we are: All shifts are extremely crisp when the tranmission is cold. The 1-2 shift will chirp the tires, and seems to occur at the right speed and RPM reading. 2-3 and 3-4 are superb, and the tcc locks as well.


As the transmission warms up, it starts to go to heck. After about 10 minutes of driving, the 1-2 shift hangs in gear, and seems almost to be in neutral. Sometimes it engages very hard after it revs, and sometimes it slides into second. 2-3 and 3-4 are not affected, and are still great. downshift from 3-2 is very quick, and the 2-3 upshift will chirp tires.

What could cause such a bizarre behavior?

all gears seem to have great holding power, but that 1-2 shift is really worrying me. Any advise?


Thanks!

[VileZambonie]

Is the TV cable adjusted properly? What do you mean the 1-2 shift hangs in gear? You mean you have a late upshift?

[Toehead]

The tv cable is adjusted properly.

It doesnt exactly shift late... It will pull in first, then it will feel like it is thinking about shifting. The engine will rev almost freely, like it is in neutral. Then, it will either engage hard into second after a few seconds, or slide slowly into second, depending on what kind of mood it is in.



Thanks!

[VileZambonie]

So it slips 1-2

Here are some suggested items to check. If you paid this guy to build your trans best bet is to have him pull it apart again and do it right this time.

Throttle lever and bracket assembly incorrectly installed or damaged.
T.V. cable broken or damaged.
Throttle valve sticking.
T.V. bushing turned in its bore.
1-2 shift valve train stuck.
Valve body assembly gaskets or spacer plate incorrect, damaged or incorrectly installed.
T.V. limit valve, line bias valve or accumulator valve stuck.
Valve body face not flat.
2-4 servo assembly apply pin too long or short.
2-4 servo seals or O-ring seals missing, cut or damaged.
2-4 servo assembly bore damaged.
Restricted or missing 2-4 servo assembly oil passages.
Porosity in 1-2 accumulator housing or piston.
Second accumulator piston seal or groove damaged.
Nicks or burrs in 1-2 accumulator housing.
2-4 band worn or incorrectly installed.
Oil pump assembly faces not flat.

[Toehead]

He "washed his hands" of my car, lame as that is.


I'm going to bring it to a nice transmission shop. I'm sure it's something stupid. I'm willing to bet that it's just the seperator plate, or a step in the instructions that was left out.

[VileZambonie]

So you paid this guy to do this and he washed his hands of it? I hope he refunded you.... Did he just install the shift kit and the servo?

[Toehead]

yes, although I havn't payed him a cent yet.

He really is a good guy and has done very well before, I guess transmissions just aren't his thing.

[VileZambonie]

Guess not. Start over with a new shift kit and seperator plate. Make sure you install the valve body gaskets correctly. Don't use grease either, use vaseline to hold your parts in place. Take the entire valve body apart and clean and check each bore, spool valve, spring etc