4L80E slipping/grinding | Chevy Silverado and GMC Sierra Forum
Hi guy's, I have a 2003 GMC Sierra 2500 HD with a 4l80e transmission with 120000 miles on it. I had some issues with the the truck when slowing down from 4th gear to 3rd gear (around 45-50 mph) the tranny was slipping and doing a grindding noise while exiting from the highway. And also notice that it does it when I let off the throttle at 60-65 ...