I don't want to get too far down a rabbit hole, but the 4T65 did pretty well for a long time on a lot of cars. They did lots of fleet service in Ventures, got lots of beatings in Police Impalas, got abused in a bunch of late 200x Pontiacs, and held up well enough that Volvo put a bunch of them in their sedans and SUVs for a while. The only difference between the FWD and AWD versions was the PTO, and I've never heard of a 4T65 PTO failing. Yes some have had issues, from defects or beatings or a combination I suspect, but they weren't [1990s Chrysler automatic transmission] bad, similar to what you describe.

I have to agree though: Adding paddle-shifting to a 4T6x, especially behind a big V-8, is just plain dumb.

Considering the 4t80e fits decently in all those 5.3 cars... they should have just created a 4t80e with a LS bellhousing etc so then the trans could be appropiately sized for it.

I agree entirely. I don't understand why they put the 4T80 under the weak-kneed Northstar but not under the 5.3 . In my opinion it would have been better the other way around.

Thanks. I think that the trans was replaced, and there is a problem with the TFP compatibility. How can i tell whether i have a 4 wire or 1 wire TFP without removing the side pan?

Look at the wires going in. Open the loom.

Bellhousing and wiring I think. Because the 4t80e is easy to adapt to a LS or 3800, but its not "proper"
And the wiring and stuff goes slightly unique down the northstar road instead of LS pcms or 3800pcms.

Also It was an expensive transmission and it weighs, I Think, more than the 5.3 engine does.

That differential being the key thing, I think, to the success of the 4t80e. With the kind of abuse 3800 supercharged engines in 4000 pound cars saw, it was just assinine to think the same car with a 5.3 was suddenly going to do great lol!

I agree.

What I'm really asking is: GM, with the ability to decide to do either one then wave their magic wand in the direction of the swarm of engineers, could have chosen to put the 4T80 under something besides a Northstar. They could even have gone nuts and put a 4.8 or 5.3 on it and shoved it into a Express vans when the Euro vans started taking over. Or something.

Sure would have been neat.

based on the upper end power of the N* plus the late-year power they finally were putting out just generally, the northstar should have had the 4t80e.

But the 4t80e should have been applied to fullsize Park Avenue, (esp supercharged), 3.5 Aurora, Bonneville , anything that had a 5.3 or 4.8 FWD, and possibly those 3.5,3.6,3.9 engines that I do not know anything about(did they use 4 speeds lol)

I wish my park avenue had a 4t80e especially since the debris I found most likely came from the differential because of the fact my differential lube pipe was compropmised.