2016 GMC Sierra 1500 CC Z71 8L90 2nd to 1st downshift issues

SierraMyst · June 19, 2016

Well since you kind of know what it possibly could be, you can always print all this info I've posted and make a case to see if they will expedite trying to actually fix it versus calling it "normal" because now we know it's not normal. Now you know when the relearn doesn't work, and the adaptive fast learn transmission procedures don't work, and the valve body and TCM don't work, its the transmission with a new torque converter. That way you don't take it in the first day and the relearn it and give it back, then the next trip they do the next thing and give it back. Don't accept the truck back until they drive it and make sure it's fixed.

Yeah... My truck does the same thing as what you listed in your first post.

My build date is also 10/15, which is before the new torque converter roll out of 02/16.

Thats gotta be it.

What dealer in VA did you deal with? Maybe I can have my dealer service GM call your dealer service GM.

4emeryj44 · June 25, 2016

Awesome! It's unfortunate but anyone of us on this forum could have gotten that bad Tranny! The important thing is you went about it correctly and level headed. My experience has been....GM backs their products much more than the other manufactures and always have! Which means the dealership will go out of their way to fix problem for you. I dare any of you to go play these games with Fiat/Chrysler on something like this.

Give it some time the normal herky/jerky will be there for 1500 miles at least! And then POOF! you will not be analyzing every freaking shift point and trying to recreate the same jerkness around this corner at this speed ETC. You will be driving it and thinking WOW it's gone this thing is smooth? I can't even feel it shift WTF? Glad you got the butterness now BRO!

Thanks for Posting again so others can follow the outcome etc!

Yes I absolutely feel I went about this whole thing very well. SO another update, the GM Liaison contacted me the other day for a follow up. She wanted to make sure everything went well, I received my truck back and that I was satisfied. I told her that so far so good and I'm going to continue driving the truck until it's out of it's learning timeframe and see what the end result will be. So they ended up offering me a full extended warranty on the truck because I had so many issues so early on in the trucks life. I was very appreciative of that, and I thought that was a very fitting offer from them. UNFORTUNATELY I had already purchased a full extended warranty. I asked (since they offered) for a maintenance package for the truck, and they offered me a 54 month / 45,000 miles - 6 services for the truck after I come out of my original maintenance service plan at 24,000 miles. So again, I believe that GM has done a fantastic job with handling my vehicle, my case, and me as a customer as a whole. I've purchased a brand new GMC Sierra 1500 in 2004, this truck, and will continue to buy GM truck products probably for the rest of my life.

This goes to show that given any situation in life, if you handle these types of things properly and respectfully, 9 times out of 10 you'll get a desirable response/outcome from whomever you are dealing with.

Also, the transmission is still a little herky jerky, not nearly what it was doing before, but I will wait a good 1,000 miles or so and see if she settles in to the new shifting style and what not.

mookdoc6 · June 28, 2016

Wow! That is fantastic some of the experiences I have read on these posts seem outlandish to me on how their situation was handled by Dealer, GM etc. Anyway it looks like your looking to clean up the shifting in your GMC 2016 8speed? After it settles down 2-3000 miles etc. Let me know if it has idiosyncrasies still related to the 1-2-3 gears? I have noticed that I am a feather foot on the pedal and that will certainly allow the AFM to activate/deactivate etc. and hence you will feel pedal movement and shifting? If that is the case then I believe you have the same situation as me.

I have contacted Blackbear myself to clean up this matter and the others I have talked too had same issues and have disabled/ or controlled when to activate AFM 60+ etc. I believe I am going this route. Good Luck

4emeryj44 · July 1, 2016

Wow! That is fantastic some of the experiences I have read on these posts seem outlandish to me on how their situation was handled by Dealer, GM etc. Anyway it looks like your looking to clean up the shifting in your GMC 2016 8speed? After it settles down 2-3000 miles etc. Let me know if it has idiosyncrasies still related to the 1-2-3 gears? I have noticed that I am a feather foot on the pedal and that will certainly allow the AFM to activate/deactivate etc. and hence you will feel pedal movement and shifting? If that is the case then I believe you have the same situation as me.

I have contacted Blackbear myself to clean up this matter and the others I have talked too had same issues and have disabled/ or controlled when to activate AFM 60+ etc. I believe I am going this route. Good Luck

Yes, i am very pleased so far with everything. Obviously I would rather have NOT had any issues with my truck, but I did and I believe myself, the Dealer, and Gm have all handled it well. The transmission so far is a little herky jerky here and there, but seemingly it is getting better by the day. I will give it a good couple thousand miles until I feel the end result is the end result. The major deficiency of the clunking from 1-2-1 is pretty much gone, so that was the main reason I had taken it in.

As far as the AFM, I probably would agree in the fact that disabling it makes the truck run a little better, but honestly i'll just put the transmission into M7 and then AFM doesn't work anymore, that way I don't require a tune which will void my warranty. With everything that's gone on with my truck thus far, I DEFINITELY do not want a tune on it and give an excuse for a new transmission replacement to have a BILL associated with it. But yes I believe that these trucks would greatly benefit from a tune.

MOhunter92 · July 7, 2016

Mine does the exact same thing. Terrible, jolted and harsh down shift from 2-1. Told it's normal by my dealer without them looking into it. I'm going to mention this again.

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mookdoc6 · July 7, 2016

Again, how many miles?

4emeryj44 · September 21, 2016

Again, how many miles?

I am at 17,XXX right now

4emeryj44 · September 21, 2016

****UPDATE*****

Alright, so here's the deal with the truck at this point. I thought it was fixed but apparently not. So, I will explain what is going on and the new plan of action.

So, I gave the truck a couple thousand miles like I mentioned previously in the post, and I went back to the dealership with similar issues. The HARSH 1-2-1 shift where it felt like I was being rear-ended is in fact gone, but over the couple thousand miles it still never got much better with the in city driving, sloppy shifting, unpredictable, often jerky, and clunky. You never know how the truck is going to shift, sometimes its perfect, most of the time it sucks ass! But, there's been a few situations here and there where I still got the decently harsh shift on the 2-1 downshift. If I press the gas pedal enough to where it would normally shift to 2nd gear and I abruptly let off, I can get it to clunk horribly quite often. Now you might ask why would I do that, I wouldn't normally do that while driving, well yes I would. Say you are at a stop sign and behind a couple cars, they move forward, so I hit the gas enough to creep forward and it will try and shift to second, then I let of because I'm coming up to the stop sign and BAM! there it is. I honestly HATE driving the truck, I bought my dream truck and I don't even enjoy driving it.

Now, since I told you what all is still wrong wit the truck, let me get into what I'm doing about it. So I went to the same local dealer that I've been dealing with, and once again they've been great with me. I immediately ask for the service manager and told him everything the truck is doing and I mention I want to "lemon law" the truck and I don't want it anymore. BTW it more than qualifies for lemon law with the amount of times it's been in the dealer for the same recurring problem. He said, alright, give me a few days to do some research, talk to some Engineers and we can come up with a solution. I wait the few days, they have slotted an Engineer from the factory to fly out and look at my truck. Now it's been a few days since I've heard from them, they don't know when the Engineer is actually coming out, I'm letting it all play out on it's own. They completely ignored the fact that I mentioned I want to "lemon law" the truck. Service manager said the engineers thinks he might have a solution to fix the truck, which in my mind tells me that they have not a clue what's wrong and they want to see for themselves what the hell is going on with this truck.

So here's my dilemma. In my opinion, coming from a GM business stand point, I would think this. If a customer is having THIS many issues with one of my products for about the 5th time in 17,XXX miles, I would without question take the truck back and figure out a way to get him/her a different vehicle. Why keep "not" fixing it and letting him drive a product that is defective or a lemon. I personally would take the truck back, get it to whatever engineering department it needed to go to, rip the truck apart and see what the hell is wrong, put out a TSB or a fix for other trucks with this issue, and learn from either a deficient product or maybe bad assembly line put together. IDK, just my opinion from a business stand point.

Do I go drop the truck off at the dealership and say, "I don't want the truck anymore" and let them figure it out? I'm kinda over the truck, I don't like the 8 speed, I have no confidence or faith in this truck anymore. I would honestly prefer to find a couple year older truck with 6 Speed and drive that. Again, I feel that the truck will just sit at the dealer, they will replace whatever they think is next and give it back. I know they have to lemon law it if I say that's what I want to do. Do I give it to them and continue this process of "fix it" and give it back and drive it another couple thousand miles to just be unhappy with it again? or do I just call it quits? If I give it to them to fix and they kinda fix it, can I then not lemon law it? Do I talk to HEAD of dealership to get a different truck? I've talked to GM higher ups in the past, they seemed more like middle men to me, but I'm just not sure what to do at this point.

Brianibew · September 21, 2016

If it were me, and I truly had a black and white lemon law case, I would pursue the lemon law filing and get a new truck. You used your hard earned money for a new truck, and ended up getting a truck that Chevy just cant seem to get fixed (aka: a lemon). With any luck, you'll end up with a new 2017 that runs the way it should.

mookdoc6 · September 21, 2016

****UPDATE*****

Alright, so here's the deal with the truck at this point. I thought it was fixed but apparently not. So, I will explain what is going on and the new plan of action.

So, I gave the truck a couple thousand miles like I mentioned previously in the post, and I went back to the dealership with similar issues. The HARSH 1-2-1 shift where it felt like I was being rear-ended is in fact gone, but over the couple thousand miles it still never got much better with the in city driving, sloppy shifting, unpredictable, often jerky, and clunky. You never know how the truck is going to shift, sometimes its perfect, most of the time it sucks ass! But, there's been a few situations here and there where I still got the decently harsh shift on the 2-1 downshift. If I press the gas pedal enough to where it would normally shift to 2nd gear and I abruptly let off, I can get it to clunk horribly quite often. Now you might ask why would I do that, I wouldn't normally do that while driving, well yes I would. Say you are at a stop sign and behind a couple cars, they move forward, so I hit the gas enough to creep forward and it will try and shift to second, then I let of because I'm coming up to the stop sign and BAM! there it is. I honestly HATE driving the truck, I bought my dream truck and I don't even enjoy driving it.

Now, since I told you what all is still wrong wit the truck, let me get into what I'm doing about it. So I went to the same local dealer that I've been dealing with, and once again they've been great with me. I immediately ask for the service manager and told him everything the truck is doing and I mention I want to "lemon law" the truck and I don't want it anymore. BTW it more than qualifies for lemon law with the amount of times it's been in the dealer for the same recurring problem. He said, alright, give me a few days to do some research, talk to some Engineers and we can come up with a solution. I wait the few days, they have slotted an Engineer from the factory to fly out and look at my truck. Now it's been a few days since I've heard from them, they don't know when the Engineer is actually coming out, I'm letting it all play out on it's own. They completely ignored the fact that I mentioned I want to "lemon law" the truck. Service manager said the engineers thinks he might have a solution to fix the truck, which in my mind tells me that they have not a clue what's wrong and they want to see for themselves what the hell is going on with this truck.

So here's my dilemma. In my opinion, coming from a GM business stand point, I would think this. If a customer is having THIS many issues with one of my products for about the 5th time in 17,XXX miles, I would without question take the truck back and figure out a way to get him/her a different vehicle. Why keep "not" fixing it and letting him drive a product that is defective or a lemon. I personally would take the truck back, get it to whatever engineering department it needed to go to, rip the truck apart and see what the hell is wrong, put out a TSB or a fix for other trucks with this issue, and learn from either a deficient product or maybe bad assembly line put together. IDK, just my opinion from a business stand point.

Do I go drop the truck off at the dealership and say, "I don't want the truck anymore" and let them figure it out? I'm kinda over the truck, I don't like the 8 speed, I have no confidence or faith in this truck anymore. I would honestly prefer to find a couple year older truck with 6 Speed and drive that. Again, I feel that the truck will just sit at the dealer, they will replace whatever they think is next and give it back. I know they have to lemon law it if I say that's what I want to do. Do I give it to them and continue this process of "fix it" and give it back and drive it another couple thousand miles to just be unhappy with it again? or do I just call it quits? If I give it to them to fix and they kinda fix it, can I then not lemon law it? Do I talk to HEAD of dealership to get a different truck? I've talked to GM higher ups in the past, they seemed more like middle men to me, but I'm just not sure what to do at this point.

Yup, Sorry to hear it man! Be cool do what you gotta do and if they decide not to fix to your satisfaction maybe 3rd time is a charm by all means tell them they "GM" will be buying this back!

mookdoc6 · September 21, 2016

Like I have said, "I have pedal feel in mine meaning I can feel the shifts in 1-2-3 and back down but a there is no banging or thumping or harshness?" Once in awhile it has a little harder knockdown when coming to a stop....but just more abrupt pedal feel of transmission though.

Makes me wonder? I had almost 400 miles on my truck when purchased new? Did I have a janky transmission too that was swapped out early on? I will never know......

jetfixer737 · October 1, 2016

At about 22,000 miles now, mine has the same 1-2-1 shifting issues. It's been to the selling dealer in Idaho twice, and a nearby Chevy dealer in Colorado twice, and every time I get the dreaded "Cannot duplicate" statement. When exiting the freeway near my home I've had the 2-1 downshift hit so hard it squeaked the tires. The local Chevy dealer is nice & wants to help, but their current "fix" is to tell me "Don't worry about it. You have a 5 year / 100,000 mile power-train warranty. If it blows up, we'll fix it." Another (helpful) tip I got came from a guy I know who's a Chevy salesman in Idaho. He drives one of those new, blacked-out Silverados. The trans techs at the dealer he works at are telling people "This transmission started life as a Corvette transmission, and doesn't like to be babied. So every 4-5 days or so, drive it like ya stole it. That makes it work better." I have to admit, my transmission does work better when I put my foot in it, but the fuel economy drops like a rock, and it just goes right back to its old habits as soon as I ease up. For the present anyway, there are plenty of Chevy / GMC dealerships in the Denver area, so I'm just gonna call another one and see what they have to say.

4emeryj44 · October 2, 2016

***** UPDATE *****

So, here's my gameplan. An Engineer (not a GM engineer just a service engineer) is coming in on Tuesday to see the truck. I'm going to drive the truck with him and show what all the truck is still doing. I don't know at that point whether they will sit me down and talk to me about my buyback options or not. What they did tell me is that once the Engineer establishes how long the truck will be in the shop for, they will get back to me in regards to buyback or getting me a different vehicle. I went to a local Chevy dealer today to look at some of their inventory (USED) to see if they had anything worth while.

Long story short, I talked to Manager at Chevy and they said with a buyback they are going to make me buy a new truck, cannot buy a used truck. SO here's what I'm going to do. Today and tomorrow I will research a good lemon law vehicle lawyer here in the Hampton Roads Virginia area and sit down with them sometime this week after I see what happens Tuesday and what the dealer says. If they say I HAVE to buy a new vehicle, which I don't want the same truck that just caused me a year of headaches, then I will go see the lawyer and show them all of my historical information and see what they think my chances are of successfully lemon lawing the truck.

At this point I don't know what else to do, the truck is shifting worse and worse the more I drive it. Just took it on a trip to OH and it did horrible when I hit traffic, just complete garbage. When it slams, even though I know it does it, it still makes me say "WOW" or "Holy crap" it's that bad.

mookdoc6 · October 3, 2016

Man, just tell the prick once he agrees that this is shit all GM has to do is put me in a same vehicle that does not do this and all is settled! Or the other side of the coin will be a bunch of nonsense and It will become personal and GM will still end up paying and loosing a customer for life!

jetfixer737 · October 3, 2016

I gave my situation a lot of thought and after a while I couldn't sit still for the whole "Drive it til its breaks then get it fixed scenario." This past Saturday I contacted GMC customer service & initiated the whole case file routine. Her first move was to contact the dealer who most recently worked on it and get someone to do a ride along with me. Having them try to duplicate my shifting issues in the tight spaces of the car lot isn't good enough. (If they ever really even tried to) So we'll see where this goes. Probably nowhere, but at least its documented.