Torque converter 4t65e oscillates

[rick444]

I have a good engine installed in Uolander,
Can I prevent TCC from engaging till i figure out what to do to fix the root problem.
My study tells me that sonnax has a valve kit that compensates for a wear and thereby sends better pressure.
For the time being I hate to allow needless cycling of the tcc friction material for fear of wearing it out before i can fully understand what to do. Will it wear out?
What signals the ecm to dropout? Is it the mismatch of tone signals, or simply a pressure sense? Is it really slipping?
Prior to full warmup the system behaves. So:

* WOULD COLD THERMOSTAT 160F HELP ALONG WITH TRICKING TEMP SENSOR FOR TEMP FIX?

* LUCAS ADDITIVE TO INCREASE VISCOSITY OF FLUID OR SOMETHING ELSE (STP)
PS ALL OTHER FUNCTIONS OF 4L65E WORK PERFECTLY SMOOTH AND ACCURATE.
CAN I REWIRE THE PINOUT TO SNIP THE CONTROL TO TCC TO GO NON LOCKUP IF I ADD A COOLER TO THE LINES?
I AM NOT READY TO DO A TEARDOWN YET, BUT JUST WANT TO BUY TIME AND KNOWLEDGE.
ANY COMMENTS THAT MAY EDUCATE ME ABOUT TCC ACTIVITY? THANKS 2006 UPLANDER @120K.

[robertisaar]

thermostat won't do it... generally, TCC functions are enabled in the 100-120*F range in most later factory calibration I've seen. even if you removed the thermostat completely, you might still hit that threshold, especially at lower speeds.

if you really want to disable the TCC for any reason, cut(or preferably, depin) the TCC circuit.

with a 3900: on the transmission connector, pin T(tan/black) or on the TCM connector, pin 1.
with a 3500: on the transmission connector, pin T(brown) or on the PCM connector, pin 39 of connector 3(grey).

[rick444]

3500 lx9

thermostat won't do it... generally, TCC functions are enabled in the 100-120*F range in most later factory calibration I've seen. even if you removed the thermostat completely, you might still hit that threshold, especially at lower speeds.

if you really want to disable the TCC for any reason, cut(or preferably, depin) the TCC circuit.

with a 3900: on the transmission connector, pin T(tan/black) or on the TCM connector, pin 1.
with a 3500: on the transmission connector, pin T(brown) or on the PCM connector, pin 39 of connector 3(grey).

ROBERT, THANKS FOR THE INFO. I WILL DISCONNECT THE TCC. wHERE DO YOU THINK IS THE EASIESTCONVIENT CONNECTOR TO GET TO?
The reason to depin is to save the tcc friction material till i decide a root cause fix. Probably the tcc valve fix kit from sonnax.
The tx is otherwise perfect. Oscillation is smooth but real. Eventually would wear out friction material. Agree?
I wonder how the tx knows that the tcc clutch is iffy? Slip detection from tone wheel comparisons?

I may find myself lowering the left side of the cradle in the weeks ahead in order to get the side cover off for the new tcc slide valve simplified fix w/o reamer rework.
Some people say 5 hrs, others take 15 hours. Did you ever do something like this in car?

[robertisaar]

not sure which is easier to disconnect, I'm not familiar with that platform.

oscillation is odd, I do know that a lot of GM 4T60E/65 applications from ~98 up have it happen to some degree intentionally. GM states it has something to do with powertrain isolation, but I much prefer a fully locked converter. the TCC material is supposedly able to withstand a decent degree of constant slip, but I would rather it be avoided if at all possible.

TCC slip can be measured via the crank sensor and transmission's input shaft speed sensor. any RPM difference between the two while the TCC is locked is slippage from the TCC itself.