So Ive got an issue. New rebuilt transmission, new converter, dragging at idle sometimes. It does it when cold all the time, if I dont give throttle, it stalls and dies immediately when going from park/neutral to any drive gear, forward or reverse. When its warm, sometimes it does it, sometimes it doesnt. When it does go into its fits, the converter or transmission sounds like its making a rattling noise. when it goes into a moving gear without issues, it doesnt make any noises.

Ive pulled the valve body, took it to a shop, TCC circuit is holding 20" of vacuum, TCC solenoids are workiing properly. HP tuners shows lockup isnt being activated when its dragging. Pump pressures are all within spec according to Sonnax. Return line from cooler is pumping about 1.5 quarts every 20 seconds.

Now its done this before, same converter company, back when it was a single disc lockup. I installed the Sonnax Lube regulated pressure regulator valve. Problem went away. Fast forward 1200 miles, I did a pull in 3rd, shifted manually into 4th at 130mph, lost everything. Pump took a **** and killed the transmission. Sent the converter in, rebuilt the transmission again, installed the setup, had a vibration from 4000-7000RPM. disconnected flywheel from converter, vibration gone. Sent converter in. Converter company said nothing was wrong with the converter. Spent 8 hours removing turbo setup to check compression, compression was within 5psi of each cylinder. Converter company said problem was in transmission. Took trans to builder, builder said nothing wrong with trans. It had 60 miles on it...Converter company suggested I upgrade to a triple disc. Done.

Now rewind to last Saturday. everything was great, about to head to the track, wanted to test the Rossler Transbrake. New trans and converter, about 600 miles on them, pulled to a stop sign, got on transbrake for 3-4 seconds, built 8lbs boost, left off brake at about 70% throttle, brake worked great. Came to another stop sign, car stalled out and died. Drove another half mile home, pulled into garage and stopped. Car stalled again and died. Been waiting to go to the track for 7 years in this car. Got to the track, car makes the first pass with a 9.7@143 with a 1.7 60ft. Second pass was a 9.58@149 1.53 60ft. Got kicked off the track.
Been trying to figure this out ever since.

Any ideas? Not naming the converter company yet, but I'm on converter #3 in less than 6 months. Transmission is a 4L80e

 

Lots of views, no suggestions?

 

Wasn't hard to figure out where the converter came from... just got a triple disc from them as well - and looking forward to using it. The best thing you can do in this situation is to remain completely objective throughout the process. But, by your own admission you are pretty hard on this thing and the operator plays a role.

Last time I checked there are something like 6 different readiness states and modes for the TCC? So it helps to be clear if it is commanded ready or engaged/released. I am going to assume that you have the PWM tuned out or deleted, so the circuit should act as a binary switch (on/off). Do you have a capsule in the input shaft? There is also the possibility that any misfire codes are monkeying things up too.

So without seeing a log and tune, or having details on the internal mods, it is tough to tell what is or isn't happening here.

 

4L80E doesn't have a capsule in the input shaft.
I would be looking into the wiring, the tcc solenoid, and the trans brake.
The noise could be the pressure regulator buzzing and high line. What boost valve? Ever do a pressure test? These can have 600+ psi with the pressure solenoid operating fine.

 

Solenoid tests the same ohm wise as a new one. 12 volts applied to existing tcc solenoid and you cannot blow through it. Sonnax boost valve installed with Rossler spring. Did the pump pressure test, can't remember the exact pump pressures, but I wrote them down and called Sonnax, they are within spec.
On a side note, pulled the transmission last night, it' at the trans builder now. Dumped the converter, there is fine copper shavings. I'll update what I find wrong.

 

Huh, mine is currently in the car for mock-up so that was just an assumption. Learn something new everyday.

 

I am not 100% sure on a 4L80E but on a 4L60E you should be able to blow through the solenoid when there is no power applied.

 

Static pump check ok. You also said it works ok sometimes. TCC solenoid is open with power to it.

 

Well heres the deal. It always drags when cold, stalls the motor out. Have to give it gas and ride the brake to get out of the garage. After driving a bit, it will loosen up usually. Sometimes it drags but just lugs the engine down. Sometimes it doesnt. For instance. Last Friday I drove the car to the transmission shop, let the builder listen to it. Sounded like it had rocks in the converter. He wasnt sure what it was, said to pull the trans and we would go through it again. If it wasnt the trans, get ahold of the manufacturer of the converter. Went to leave, it was acting up trying to die, rode the gas and brake to leave. Made a left turn, 2 blocks down got to a stop sign, motor lugged. Made a right turn, two blocks down stoplight. Car idled fine, no dragging, no lugging, was perfect. drove 20 miles, 10-15 different stops to my kids school. Car was perfect. Turned car off went and paid for my kids field trip. Two minutes later go back to the car, start it, put it in drive. It dies. 8 stops on the way home, car died at all of them. parked the car. Drove it the next day, it lugged the engine at most of the stops but didn't die.

 

On a side note, just before I pulled the trans last night, checked pump flow, I'm getting almost 1.5 quarts every 20 seconds at idle on the return line.

 

Did your transmission builder add the converter limit valve blocker or spring?

 

This guy? https://www.sonnax.com/parts/2025-tc...ator-valve-kit

https://ls1tech.com/forums/automatic...-dragging.html

 

Yes that part is in there. Valve body was removed and taken to a valve body refinisher shop. Vacuum test on that port holds 20" of vacuum. Plunges in and out with no problems.

 

does it sound like this?
https://ls1tech.com/forums/automatic...eel-noise.html



copper shaving you say? I saw some copper color bushing in the pump, and I assume there are others also inside the trans. Makes me think thrust? thrust or converter end play "pullout" comes to mind.

 

Did you install the sonnax line to lube valve? I had the same issue with my 80e with a circle d triple disc and this fixed it.
Sonnax
34200-14K

 

he said something about finding copper shavings, although maybe unrelated.

Hmm makes me wonder: did op use a later 4l80e without the extended rear lubrication fitting from the trans line? Trans would only go like 50 miles or something if so.

 

That is not the valve I'm talking about. The converter limit valve is in the pump.

 

Yes the extended fittings for lube are in the trans. Yes the converter limit valve was installed. That came with the Rossler trans brake.
The problem was the pump, again. Previous converter that had the vibration started wearing the pump. Pull with the transbrake finished it off.
now for the good news. Talked to the converter shop owner today. He is overnighting me a brand new converter and paid for parts inside the transmission that got torn up. I'll be sure to keep this thread updated.

 

Fing converter and pump, my two least favorite parts, the most two important on the entire car apparently. Not going anywhere without them both being A+

 

1000 mile old overdrive planetary taking a **** on me also. This one is #2. Gotta find something stronger. Last one stripped the splines completely out. This one is working on it, tops of the splines are losing material and turning more into an A shape.