I had a 4l80e Swapped to my 2006 Silverado, it was good for about a month until the whole Bell Housing grenaded. After that I've been having nothing but problems with my transmission overheating.
So far it's overheated 2 and now on my 3rd one witch Today again after 130 miles it overheated. I've tried everything possible such as new lines, TruKool 40k cooler, New converter, 3 trannys now, New radiator, New sensors, New fluid and that's pretty much everything.

Anyone else have a suggestions on what could be causing this?

 

Pinched cooler line?

That trucool should be blazing hot when your transmission is supposedly overheating. If not, you've either got a fluid flow issue or you have a faulty harness causing the temp sensor to skew. Or. you could have a lockup issue.

 

Possibly and issue with the pcm?

How are they shifting, etc.. before they are overheating? Converter locking up as it should?

Have you dropped the pan on them to verify problems?

-Chris

 

What is the temp? How do you know it is overheating? Like said above, the cooler will be hot. Are you running through the factory cooler too? What stall are you running?

 

That's what I'm guessing

Tranny shift's good and everything, it overheats at cruising speed in the highway 3rd or 4th gear (3.23 gears) Converter is stock.

And no, as this is my 3rd transmission within 200 miles with the same problem.

Not sure what the temp is, But I have a trans temp getting here tomorrow. I know it's overheating because on my Dash It starts blinking "Transmission Hot" and it feels like it engages Tow-Haul and RPM's go up.
No at first it was thru the radiator then cooler but now it's directly to the Tru-Cool 40k. I'm on the stock stall.

 

Sounds like the converter isnt holding lock-up to me...

I cooked my current 60e the same way... drove great but suddenly stopped holding lock up... or it would cycle... tranny hit 230 before I realized it...

If you have swapped converters and have been through 3 trannies... I'd look at wiring, pcm, cooler lines, etc... sounds electrical more then mechanical but I could be wrong... Not a tranny guru by anymeans.

-Chris

 

If the converter wasn't holding lockup he'd hopefully have a code for TCC Stuck OFF.

 

Well I've been driving it around for some time and at some points I get Transmission Hot message on my dash but I got my AEM Gauge hooked up to the pressure port on the Trans to read the temps
But the weird thing is that at some points when it shows hot It's only ~160-170F, but the transmission acts weird it revs up and shifts hard. Sometimes I see temps of 200-210 but it doesn't show Transmission Hot.

 

It sounds like the most likely culprit is the ECM temp sensor or harness in the transmission. The "Hot" message comes on at 275 degrees.

 

So am I better off just replacing the ECM?