4t60e torque converter lockup

[my580e@windstream.net]

My 1995 Grand Prix SE has random torque converter lockup.
I tested ohms on tcc & pwm solenoid both in range
Applied 12v to trans and grounded tcc solenoid wire and can hear it click.
Disconnected pwm solenoid and test drove. No lockup
Ran ground wire from tcc solenoid to inside car and manually grounded when up to speed sometimes would lockup sometimes could see rpm's drop slightly like partial lock up was occurring.
I rebuilt tranny approx. 5000 miles ago. Almost every thing that moves is new except solenoids. Dropped pan is perfectly clean.
Anyone have any suggestions.
Also the valve body was reamed and sleeve was put in.

[3400-95-Modified]

Did you do the Trans Go shift correction kit? and or buy the Sonnax replacement valves for the TCC solenoid? If its just the aluminum valve it could be sticking in the bore. The new/replacement ones have teflon sleeves on them as well as being anodized to prevent sticking. And the trans go kit makes you install a few stiffer return springs as well as open up the orifice of the TCC solenoid to give a firmer TCC apply.

[my580e@windstream.net]

Yes I did the Sonnax valve replace . Reamed with steel sleeve.
I just had the side cover off and replaced the TCC & PWM solenoids and also temp. sensor. Trans temp was reading 220 to 245 deg with scanner but infrared temp hottest spot was 200 deg on side cover and 147 deg on bottom pan.

[3400-95-Modified]

Any change in the trans temp since the sensor swap? Case temp will not directly relate to oil temp.

[my580e@windstream.net]

Added a trans cooler temps are 175 deg. to 210 deg. with scanner. Converter still randomly locks up.

[TurboGTU]

office screen in the channel plate missing or broken would be my guess if its doing it in 2nd gear.

[3400-95-Modified]

Shouldn't be a TCC lock up in 2nd gear. At least mine never tries to.

[TurboGTU]

That's right. 2nd circuit will feed TCC supply and screen restricts flow like a orfice tube in a A/C system. Too much flow and Tcc will apply random without being commanded.

[robertisaar]

stock calibration allows for TCC lock in 2nd gear if the trans temps get high enough.

[3400-95-Modified]

That's right. 2nd circuit will feed TCC supply and screen restricts flow like a orfice tube in a A/C system. Too much flow and Tcc will apply random without being commanded.

I know how to build a 4t60e but I don't know all of the fluid paths on the valve body... LOL but yeah that makes sense!

[TurboGTU]

I know how to build a 4t60e but I don't know all of the fluid paths on the valve body... LOL but yeah that makes sense!

I'm still learning.

robertisaar

I always liked the transgo mod where the tcc spool valve is grind down as not to disturb oil flow to the converter. I know its done to the 3t40. Haven't bought a trans go or superior shift kit for the 4t60e. The OE solution seems dumb. Because now your lugging the engine and heating the coolant and trans uses the heat exchanger in the radiator to match the engine temp. You up north guys need the OE setup. Us south guys omit the radiator lines completely and run a air cooler.

[3400-95-Modified]

I'm up north and I just have an air cooler... I don't run the car in the winter though so that's why.

[my580e@windstream.net]

Just for clarification when pcm is commanding lockup is when random lockup occurs.
Now for the latest. On a trip from eastern PA to Ct. 180 miles into trip cruise control set at 70 mph. trans temp. 225 deg. in drive (4th gear)torque not in lockup rpm's suddenly increased. Turned off cruise and shifted to neutral, pulled off side of road. Inspection reviled no external problems. Put tranny in 3rd and finished trip no other problems.
On return trip disconnected tcc and pwm solenoids and ran 3rd gear fist 180 miles no problems. Last 200 miles shifted to Drive (4th gear) no problems.
After trip was compete I went to drive car and trans didn't want to engage in reverse or drive let run in park a few seconds and every was OK. Next day same thing happened I'm ready to tear down again but don't know where to look for problem. HELP!!!

[TurboGTU]

Well seems like you diagnosed the electrical. A pressure gauge can help diagnose the hydrolic system. Maybe modulator is out of adjustment if a aftermarket adjustable or even a torn TCC seal or broken input shaft seal. Might even be a defective torque converter

[my580e@windstream.net]

Pulled trans and disassembled found some metal shavings in filter and 3 small pcs. in pan but none on magnet. Can't find where it came from assuming it is coming from torque converter. Wish I could find out for sure.
All the seals looked ok to me. Taking parts to trans shop to have them look for problem. Is there any way to check converter?