ls1mike wrote:
Another thing is the 6L90E is better than the 6L80E. One extra clutch per clutch pack, it is 35MMs longer than an 80E, strengthened input and output shaft with wider gears. 2500HD and 3500HD get the 6L90E and don't suffer the problems people encounter with the 6L80E in half tons. Heat failures and torque issues due to AFM causing the torque converter to go in and out of lock up.
The 90E first gear is 4.030 vs the 80Es 2.482. That was a huge improvement. 4th gear is 1 to 1 in the 90E and the 80E is 3rd. It diffidently improved the usability of the 6.0 for towing.
I have one of each at home. The 90E is in my truck. The 80E is in my 2014 Caprice PPV (never in police service) The 80E is behind a 400RWHP/400FT/LBS of torque 6.0.
But totally apples to oranges, save for the clutches and shafts being "stronger".
One is built to haul trailers, the other is built to haul @ss!
But you know that already, and in a half ton, the deeper first gear isn't needed with smaller tire diameter, lower designed duty cycle for towing, lower towing "rating" and built more for cruising than towing...the reason everyone berates half tons here.
However, I've never had issue getting 14klbs trailer moving with my 6L80E, other than the tq converter was defective since day 1 and it would shudder getting a larger trailer moving....up until it cut loose at about 60k miles! New trans does not shudder now.