irok

I get 30 plus years out of my 700R4 that run's 1.45 60ft's and I wont have to worry about the 4L65E lasting as long.I have never run across anyone that has had 6 or 7 failures with a 4L65E as friends 6L80 has had

BadAV

Then you haven't talked to forced induction truck guys that had 4L60/65Es. Again, getting all that weight moving with FI full torque right off the line is the big issue that tears them up, no matter how well you build them. Cars are not a big problem. It was in my opinion GM's poor engineering choice to put a 4L60/65E in a heavy truck in the first place.

z06clif

The C5 had some very well known problems that should be addressed....i.e. steering column lock , gas gauge to zero to name 2

Clif

irok

Not talking about trucks here.In 3,200 lb supercharged C6's running 1.30 60ft's there hard to beat

BadAV

You weren't, I was. 6L80 holds up better in heavy weight vehicle applications; 4L60/65 isn't bulletproof in that OEM application. The information is still relevant for people to see. Many of us have a truck as our DD.