Anyone here have a GM with the 8-speed auto? Any GM techs around?

qslim

qslim

The Man with the Big Yellow Car
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I made the mistake of buying a '16 Silverado when it was new, and have been battling GM and the dealers since with harsh shifting issues. The thing tows like a dream, drives fine, fits me very well, but damned if it doesn't shift like a dump truck (I've never driven a dump truck, just being poetic). There was a point a few weeks back when it was dumping snow and I was crawling slow up over a pass that I thought the dude behind me rear-ended me - turns out it was just a 2-3 upshift. It's at the point that I couldn't even sell it because no one test driving it would pay anything near what it books for.
All the dealer says is "GM doesn't have a fix for it". Anyone else in here have experience with them?
 
I went through something similar when we bought a 2013 Ford Focus brand new. If you don’t know about their transmission issues by now, you haven’t been reading the news. Let’s just say that I feel your pain.
 
The few I have driven never had that issue...

My dad has a 13 powerstroke that would shift like you describe. He had a couple of faulty shifter solenoids. He too went thru hell trying to get the dealership to replace them. In the end they replaced all 6 of them for him. That was back in 2015 or so and he hasnt mentioned a problem since.
 
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I had a 545RFE "Dodge Ram " transmission that did this very thing.

Dropped the pan,replaced filters,added fluid and bought a tuner that enabled user to adjust line pressure in transmission......haven't had a harsh shift in 2 years.
 
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The dealer should do the 20 quart flush with the new Mobil trans fluid. My dealer did my 2019 Colorado ZR2 . There are a bunch of warranty issues ( shudder and hard shifts) with the 8l45 and 8l90 gm transmissions.

The oil flush should be under warranty.

I am going to get a tune from Trifecta after I get more miles on the truck. Only have 10000 on it and the tune will most likely void the powertrain warranty. Their tune cleans up the shifting from what I have read.
 
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