Truck has a 115k miles on it. No leaks or drips anywhere. Problem is that it downshifts harsh. And by harsh I mean I'm waiting for a u-joint to snap when it does because it's so violent. When I'm coming to a stop the 2-1 shift jolts the truck. If I'm cruising around 55mph and stand on it it bangs into gear and takes off. I plan on dropping the pan and changing the filter and adding new fluid but just haven't had the time in the 3 days I've owned it. It may be because I pulled the fuses and am going through the relearn procedure on it or it could be I'm paranoid. Otherwise it runs great. Upshifting is fine and quick. Just the down shifts seem harsh and violent. Anyone else experienced this? I've tried searching but I must not be entering the correct information. Truck does have decent service records according to car fax but I didn't see anything specifically calling out trans fluid change.

 

If it's going through a relearn that'll definitely be an issue.

It needs to learn during grandma driving so quit hammering it and drive it around slow and gently and let it learn. It can't learn smooth shift adaptives when you're getting on it.

 

The 6 speed is like that. My 17's 6L90e does some pretty horrid downshifts after a reflash until it gets its **** together after a bunch of driving. Like now as example I have down a few thousand miles since my last reflash and it's calmed down to the point of being alright. Mine is not the stock GM tune anymore though either.