2014 Chevy 1500 slips out of gear

JCmiller · December 17, 2019

This truck was my daily driver until it just quit. No issues with grinding, slipping, pulsing, whining etc. until I got in it one morning after remote start and it ran for ~10 min and it wouldn't shift into reverse. Turned it off, back on and went into reverse fine but then not drive, turn off, turn on, won't go into drive. Left it and got in another vehicle to go to work, get in the truck later it goes into drive fine, drives forward to return to spot and shut it off, no issues. Few hours later, get it, reverse, drives, shifts gears all fine until it warms up then you can feel it slip out of drive into neutral. After that it sometimes goes into gear, sometimes not. I checked fluid and it's to correct mark and clear.

I took it to a Chevy dealership where they replaced the recall on the brake vacuum pump and told me the recall for the transfer case programming that caused the transmission to suddenly shift into neutral had been completed years prior and all software was up to date. For the $150 diagnostic they said the transmission fluid was dark and burnt and quoted me $5900 for a complete rebuild.

Has anyone else had a similar issue? Fine one day then sort of okay the next?

SSdriver27 · December 18, 2019

Keeping an eye on this one. I just bought a 2014 denali with LS3 and 4L80E Tranny and the tranny seemed off on shifts when I was pulling a trailer and now empty it slips and bumps all the time. Annoying AF especially for a fairly new low mile $35k truck.

JCmiller · January 2, 2020

Gave up tinkering and took it to a transmission shop. Tranny was shot and had to be replaced...

FL335i · January 8, 2020

All I can say is it seems like the 6L80E trans likes to tear up fluid from what I've seenin 107k with my '14. Between the high temp cooler tstat and long fluid intervals..... it's a time bomb IMO. I removed the T-stat completely on my '14, my wife's '19 tahoe runs much cooler stock so I won't mess with hers. I've been doing fluid flushes and pan drops on mine every 45k. Then doing fluid flushes in between. I even added a external filter. I know a guy I work with and his '15 6L80E went at 103k. Cost $3k for the rebuild at a shop. $5,900 is nuts.