Somewhere I read that it might be possible to use a vac modulater on a 4l60e. I have a 95 Z with its 2nd trans first spent 1600 and it slipped in less then a year, now I have a TCI trans and conv even bigger $$. I have a 388 w/AFRs, 58BBk, Granateli mass air meter and more. Is the computer causing the trans not to shift correctly because of what I have. Car has not been computer tuned yet. Hate to burn up a 2nd trans. If I can use a modulater do I need to do something to the computer. I will be installing a complete rear w/ 373 next month. Any help or ideas will be ok.

 

Well if the PCM is not programmed correctly for the 383 and 58MM tb yes you will burn up one transmission after anouther.

The TransGo vacuum kit may help this inadequate programing problem for you.

 

Was wondering if I do get my computer programmed will I run into problems by using the transgo kit. Or should I program the computer with the trans still hooked up to it if thats the correct phrase. Very knew to LT1's and computers

 

I have one of the aforementioned vacuum modulator kits for the 4L60-E. Yes, it will help you work around your problem. I am not using it anymore since I do my own chips for my 4L60-E.

The vacuum modulator kit I have is adjustible and comes with a ballast resistor that prevents the PCM from setting PCS trouble codes since you will no longer have one in there. One of the other things that you might want to look at is did the people who rebuilt your tranny replace the PCS solenoid with the updated unit? GM has been having a lot of problems with older PCS solenoids wearing out or sticking which will cause the line pressure not to rise when the PCM commands it. Of course, it is very possible that stock PCM programming will cause the same problem because you do not have the correct amount of line pressure boost to enable the trans to "handle" the amount of power your engine is putting thru it.

One thing I have to warn you about this modulator kit, if you are running a big cam and have little vacuum at idle, this will cause you to run more line pressure at idle causing the trans to shift hard into gear at idle speeds. You might be ok using a 383 that has more cubes than my 350 does. In case you are interested, I am selling my vacuum modulator kit for the 4L60-E. It is used, but it is in good working order and all of the parts are there. Let me know.

 

Hey Madmax I sent you a pm, also let me know how much for the modulator. thanks Andel

 

Do they make a setup for a 700 trans as well or am I stuck with trying to change the governor springs and weights?

 

The 700r4 does not need a modulator to control line pressure because of the TV boost valve (in other words, the 700 uses the TV cable to both raise line pressure and determine shift points). Your governor springs and weights control shift points and have nothing to do with line pressure. The modulator kit for the 4L60-E has no effect on shift points as the PCM controls those directly using the shift solenoids.