A buddy has a 2007 NNBS Avalanche that killed the 4l60 earlier this year so he swapped a brake clean ******* rebuilt 4l80 in. Last week he lost reverse and it slips really bad going into forward gears while also making a terrible noise. I've never touched the truck but he said the trans temp was usually around 200* just driving around town and 210-220* on the highway which seems crazy hot to me but idk anything about autos. He said "some dude" tuned it in like 15 minutes with HPtuners a couple of weeks after he did the swap but has no idea what he did to it, and there is about 10 warning lights on the dash.

I don't know much about autos but I was thinking maybe the truck didn't know it had a 4l80 was pissed off and maybe locked the converter all the time causing it to get hot and burned it up. I pulled the tune file off the truck and told him I'd check on if it could have been a tune related issue that caused its premature death. Anybody care to check this out and point me to a thread or give me some pointers.

 

Took a quick look at the trans potion and it looks like a basically stock tune from what I saw. If it worked at all I would say its not a tune issue but a mechanical one. With swaps it basically either works or it doesnt.

Locking the converter also reduces heat, not increases it. Less slip = less heat.

 

Sounds like more of a trans issue to me. The 80e swap tune looks to be stock like @Atomic said but shouldn't cause the trans to grenade itself.

 

Thanks guys. The trans was a mystery unit so maybe it was slipping from the start which was causing the heat. Its getting a basic rebuild with a bigger cooler hopefully this week.