Hey guys, Have a new issue with my folks '96 Tahoe 4x4 w/ 4L60E Transmission. I was heading back down from NH and I got up to highway speed without an issue, stopped and started getting up to speed again and 3rd was slipping/lost it will catch if enough throttle is given, but any attempt to use cruise control 3rd will slip completely and engine RPM will skyrocket. I got it back to the house in 2nd gear, and haven't attempted to drive it since... I assume if 3rd is gone 4th would also be gone, is this a smoked transmission or maybe a clogged filter? Fluid Level Seemed good, the truck has 139xxx miles and as far as I know the fluid/filter was never changed (yay maintenance) Is this an internal harness or solenoid going bad? We haven't driven it since this happened and any insight/thoughts would be much appreciated. Thanks guys.