Alright, this is pertaining the same topic I've tried to resolve in several different threads on this forum since I got the car. My transmission guy and I have narrowed it down to one possible thing: the torque converter.

Going up hills at 35 mph, 3rd gear, locked TC. If you apply any less than half throttle, the TC will stay locked in 3rd gear to nearly 25 MPH, tach dips below 1 grand and things get nasty. Same thing happens from 48 mph and down, cept not as violent.

If you're accelerating, when you're in 3rd gear with TC locked (light accelleration), and it goes into 4th, the TC doesn't unlock and the gear shift is HARD, and it shudders, and it'* just not good. After its in 4th with tc locked, any period from 48-60 MPH, if you try to apply throttle with tc locked, it shudders bad.

I've checked TPS - it'* within range. I even adjusted it to make the downshifts occur sooner in throttle position. Thought it worked for a week, but it didn't.

It feels with the adjustable trans modulator, things have been getting worse and harder. I know it'* not from trans modulator, but more from the mileage put on the transmission.

I've made a recent discovery - a grey transmission dip stick. There'* clutch material on a transmission that was just put in with new fluid no more than 3k mi ago. And it'* pretty dark. If you want a pic, let me know.

My Question: What sensors come to mind when you ask yourself 'What would cause a torque converter to stay locked way too long, or not heed the signal to unlock with throttle applied?'.

This car has made me understand transmissions inside and out almost. Before I got it, it was just bunch of gears controlled by high levels of hydraulic pressure.

The grey material is prolly gumming up your solinoids holding on longer than comanded?
Sounds like your tranny is dying like mine :(
My torque convertor finally grenaded :?

This is 4th tc/trans though, and except for the first one, they've all done it.

Isn't this a new trans? If so, take it back. Did you get the right converter?

You need to drop the pan if your fluid is suffering.

I don't know how to tell if it'* the correct converter. I haven't had a chance to check the transmission code, but it feels a lot torquier. I'll check it when I rotate tires when I get the chance.

I told the trans shop, they said they weren't able to help, they've exhausted all of their systems and a new torque converter wouldn't work. When I take it to the dealer, they want a few hundred dollars to diagnose something that'* under warranty.

I'm not going to drop the pan, I'm going to let the trans fry itself again and let the warranty company eat the bill again. Hopefully it'll make them realize that something isn't right and make a technician look at it. I've had people look at it that are techs, but not at my dealership, and they agree with me. If they TC has been replaced four times, and the trans has been replaced four times, then it'* gotta be an electrical issue. But what?!

From reading only this thread, I assume you had the complete transaxle rebuilt, or replaced at some point. If replaced, was the final ratio the same as the original? The PCM uses feedback from the VSS (among other things) to determine shift points. The PCM is pre-programmed to shift at predetermined speeds based on throttle position, engine vacuum and rpm, just to name a few. It appears that the PCM is commanding this low speed shifting and TCC lock-up. The only way to tell for sure is with a scanner. Using a scanner, you can watch when the shift solenoids energize and release. If the TC remains locked after the solenoid is disabled, that would indicate a sticking solenoid. If you already have contaminated fluid, it is only a matter of time until the trans fails again. If I was your warranty provider, I would much rather allow some professional diagnostic time, than to keep replacing the trans & TC!

BTW, a PCM reflash may be in order here to change shift points & TCC lock-up timing. I had several PCM’* reflashed for the 4T60 & 65E’* with good results. Some that I had reprogrammed, would not energize the TCC solenoid @ less that 45 mph in 3rd & 60 mph in OD. That is what I ask for and what I got!

It'* been replaced with salvage part four times. Once with incorrect gear ratio. Now correct. I have an INTENSE PCM that has been programmed to the VIN.