What is good working temperature for 4L60E?
Mine shows 221F when driving in city, heavy traffic, A/C off.
And 203F at highway doing 60MPH.
(Readings taken from Datamaster)

Is that OK, or should I be worring about too high temp in city?

Issue is, that I lost 3rd and 4th gear, tho tranny was rebuilt 1500 miles ago. TCI Pro Kit was used. Everything points to clutches, but they usually fail under too high temperature. Or is there anything else I should be looking for? Everything seemed to be OK inside the transmission, no wear at all or very minimal wear. I just throwed TCI in, because I was checking things out. I lost a converter, so I thought it was a good time to refresh tranny as well.

Before I lost gears, I had a "sticky" 3rd situation sometimes. Lever in D and when car (stopped it wanted to take off in 3rd. When lever was moved to R and then 1 it was back to normal again. Also sometimes I had no shift from 3 to 2 under WOT. Again it was OK, if the lever was manually moved to position 2. I thought that was a sign of bad solenoids, but may I have overlooked something? Everything worked just great otherwise. Nice and harsh 1-2 shifts and under WOT it even chirped tires 2-3 shifting. No slipping or anything.

Any ideas? Cause I'll be taking tranny apart again tomorrow or so. Any ideas are welcome.

 

mine never gets that hot, but i have a seperate b&m cooler with a built in fan and larger trans cooler lines, mine runs 160f max.

 

Ok.
I lost 3rd and 4th gear completely. So took tranny apart again. clutches were worn out and the cause was a forward clutch piston with a crack in it. Checked and double checked everything else, seemed OK. New Borg Warner clutches and piston back in and tranny back together.
I also installed BM cooler. Now my tranny runs around 180-190F, seems to be OK.

But I still have the mysterious shifting problem. Sometimes it just won't shift in to 2nd or 1st. 3rd and 4th are there, but no 2nd or 1st. Problem is gone if I move the lever to 1, 2 or R and then back to D or 3. Another cure is that I stop the engine by switching ignition off and then start the car again lever in N or P.

Any ideas? I'm getting really desperate. Throw in ideas please what should I check for?

 

Today I tested for a certain pattern, how to bring transmission to this "unnormal" mode, "sticky 3rd".

It seemed to me, that it mostly happens when engine and transmission are at normal operating temperature and when I make the WOT launch from the stand-still. It will take off nicely, just before redline 2nd comes in, tires are spinning, ok everything is still ok, just before redline 3rd comes in nice and firm, no problems. OK, now I ease off the gas pedal and cruise for some seconds in third, now I completely remove the foot from the pedal and let the speed drop to ~50 mph. And now when I floor it, then there is no kickdown to 2nd and when I come to full stop then it wants to take off in 3rd. I monitored the whole thing with datamaster and it shows that solenoids are changing status as they should, but no kickdown really happen, tho it should by the status of the solenoids, neither there is no 1st tho it should be by the Datamaster. 1st comes in, if I stay stopped for some time, lever still in D. 25-30 seconds or so. Another quicker way is to move lever to 1, R or 2... or stop engine start engine.

Come on guys, I'm getting desperate. My transmission was 100 miles ago taken apart and everything were checked and double checked during clutches and piston replacment. Transmission gurus, please throw your .02 cent in to here

 

I'm going to change the valve body next week.
I'll let you know if it helped.

Meanwhile helpful ideas are more than welcome! Transmission gurus...

 

Here is the picture of piston crack:
http://www.usaraud.ee/carlogpic/536e...b4cf7ba1a4.jpg