Blbstack

Cocheese1128; what was the outcome of the trans? Were they able to source parts or just a reman? Shop near me (central Michigan) couldn’t find any parts for the 8l90… I’ve just dealt with the clunking and slamming, probably just ride it out until it no longer moves at this point.

How many miles are on your truck, Offspring22? And did they make any mention of the torque converter?

2015 6.2 with 8l90 high country 150,000. Same issues with the trans. Clunking when shifting from park to reverse. Gears slamming when downshifting or slowing down. Almost like the trans does not know what gear it wants to be in. Once you get driving everything seems to get along and drive fine. But that initial startup and shift is violent lol. Had trans flushed and did absolutely nothing. Part of me wants to have new torque converter, steels and frictions put it in and the other side of me says just drive it till she won’t anymore. the life of a GM owner

I’m back again. Lol so I was able to tear apart the box that is on top of my battery that has all the main electrical connections, not sure what it’s called. I cleaned that metal distribution plate up and added some dielectric grease and have not had a single issue since. Call me lucky I guess? but now with 150,000 miles, I am dealing with transmission issues. 8l90. Major clunking when shifting from park to reverse and terrible slamming of gears. I’m sure it’s the torque converter failure that is common in these. Anyone have and good threads to guys experiencing this? Possible solutions? honestly I’m probably just going to run it until it will no longer drive. I can deal with the clunking. I don’t want to drop 3-5k on a reman.

well guys I'm back... its been 5 months after changing the negative battery cable twice, the battery, addressing the G218 ground and I am having the flickering issues like I mentioned before. Also, the dealership addressed the power steering recall while it was in the shop, and I am still having the low speed power steering issues. The short / voltage drop is so random and it can go weeks - months before showing symptoms. I have to set up another appointment to get the issues looked at in the coming weeks. Ill try and keep everyone updated, if something new pops up. But at this point I think it'll be that GM MYSTERY ELECTRICAL ISSUE that may never be resolved and just something that you either deal with or sell the truck..

Purchased a 2015 Silverado High Country last May (2018) with 87,xxx on it (one owner). Started having the same electrical issues around October 18 and took it to a local GM shop to have the issue addressed. Tech told me me it was a bad ground cable. So instead of forking out a stupid amount of money for the tech to replace it, I purchased the part myself and put it in. Literally 2 bolts and a connector. Also the tech advised that he tested the battery 10 times and it showed it was good. He told me personally that if I change that cable the problem will be resolved. It’s a common problem he said. So at this point I was happy, less than $100.00 and a few minutes of my time and the problem would be fixed!! Fast forward a few weeks, and the same shorting out problems continued. Flickering dash, radio goes black, warning messages, dings, beeps, headlights and fog lights flickering. Started doing some research and found out about the faulty ground on the driver side dash near the windshield. Again, address that issue, a week or so goes by and the voltage / shorting out issue continues. At this point I’m fed up with it, and just drive it that way. The problems gets worse and worse almost daily, to the point where my power steering would go out and the truck would sometimes just stall. I realized that if I did something to draw more power from the battery, it would trigger the short / voltage issue. A few ways I noticed were if traction control came on due to slippery roads, or if I pulled up on the window switch, even though the windows were already up it would trip the short as well. Sometimes hitting a hard bump would trigger it. And sometimes just driving down the highway on cruise would do it. The truck at this point had a mind of its own in a way. So as you can believe, after owning the truck for about 6 months, I was pretty upset. Paid good money for it and it had left me stranded about 3-4 times at this point.. not enjoyable. So here I am, first week of March. Truck complete dead again. I set up an appointment to have it looked at. I wanted to do all I could to rule some things out. So the first thing I did was just buy a new battery. (Tech was wrong about the battery, go figure) Put the new battery in and what do you know. Truck fires right up. But a message came on in the dash that said “action needed, roll down passenger side window”.... so of course, I roll down the passenger side rear window. It goes half way down, then continues to go the rest of the way down by itself. Try to roll it back up and nothing. Lomg story short on the window issue. I check every fuse in the truck, then check them again. All are good. Have to tear apart the door panel to jump the motor to roll it back up. Ok whatever the windows don’t work. I drive the truck for 3-4 days before my scheduled appointment and have no shorting out or voltage drop issues anymore.. i took the truck in on March 4 and have them address the window issues. I hear back from them later that day and they tell me that the ground cable that is 2 months old is bad again. I explain to them that I’m not paying for a new one and that should 100% be covered under warranty. They said “we will work something out” they did not like that I changed it myself.... as far as the windows. They say that the rear window switch is bad.. and the front window regulator is bad. Have to order parts and will put them in the next day. Ok whatever just fix it. Next day day I have to call them, they say that oh now the passenger side front window switch is bad. Have to order that now. Ok so the switch is bad but you already replaced the regulator / window motor?? So here I am, truck has been in the shop 3 going on 4 days and at this point they are just throwing parts at it. Now I know electrical issues suck, and who actually knows where the problem lies, but this is getting old. The last price they gave me for the repairs was just shy of $500.00. So I’m interested to see what the end result will be. Sorry for the long post, but just wanted to see if anyone else has been having this many problems. Or if there was a different solution on their truck that was showing some of the same issues.