issue Transmissions Issues/Problems

No Tyme · April 9, 2017

My truck's transmission Has issues too. On a 2015 Sierra 2015 slt, 45000 miles. One big clunk noise from underneath and now no more power. Engine light on, d-light blinks, manual doesn't lock in, but vehicle moves, backupcamera doesn't turn on in Reverse. Reader says transmission issue with power loss. for some reason these trucks don't seem to last anymore. Pretty disappointed. Last truck was a complete fail, had to sell it back this one goes to shit after 45000 miles

You still have drive-train warranted hopefully... Lets us know what they find.

20feetup · April 10, 2017

I have a 2016 Sierra 5.3 6 speed with 9,000 miles. From the time I've bought it I've had issues with it finding a gear after coming down a hill. If I coast down a hill and then try to accelerate it will rev the engine like it is in neutral. Sometimes this will last until I'm under 20 mph's and then finally catch gear. Has anyone had this occur and if so have a solution?

nate18211 · April 11, 2017

Hey guys just want to share my transmission adventure with everyone. I have a 2016 Silverado LT with 12500 miles, 5.3 with 3.42 gears. I've always had a slight vibration at higher speeds. 65-80 mph but nothing extreme and clunky shifting. Dealer of course said it was normal. Occasionally would get a good clunk on downshifts under a load. My house is on a steep hill so usually when going up then slowing down at the top of the hill I would feel it. About 5000 miles ago it began clunking when in stop and go traffic on up and downshifts. Again dealer said it was normal. Lately it was clunking between 30-50 mph usually when merging into traffic, up shifting. Had all "computer" recalls done at the dealership.

This morning while on the highway in the third lane going around 50, it felt as if I hit a large pothole, but there was none and the engine just revved. It just popped out of gear. I pulled over and tried to go. It would shift fine from 1-3 gear then it revs and would not catch 4th. I pulled over again and tried it in manual mode. Same thing, would not engage 4-6th gear. I called the dealership they told me to turn it off and on, open and close the door to reset the transmission computer. Same thing would not go past 4th gear.

So its in the shop now. I'll let you guys know what the deal is. I'm very disappointed as this is my first Chevy and first pickup truck. I know I bought a truck but this thing lacks any finesse and new car feel. The vibration, transmission issues, and shitty idle make it feel like a POS. I know this is an unfair comparison and their quality has gone down in the last few years, but my wife and I have always leased Toyota SUV's. From day one to the vehicles return they never had an issues and felt new. My father has a Tacoma, again not a apples to apples comparison, and he has had other issues like rust. But his trucks motor and transmission have been bullet proof, I've pulled a 18 foot cuddy cabin with his truck for years and never a hiccup. The only issues came when he put "off-road" tires, then he complained about vibration but that was expected.

Update - I picked up the truck today. They found the gears 4-6 clutch hub was broken. The hub was replaced, along with the fluid, filter, pump seal, and it as flushed. They did mention that it was weird no check engine light or codes were saved. They forwarded this to GM for review. It drives okay. Same as before just works now. I'm still on edge as this is just 12,500 miles in... What else is going to break? I guess I just have to drive it. This will just be in the back of my mind.

I have to say the dealer I brought it to was not the one I use for regular service, they were great. They have a dedicated in house transmission tech. Super quick turn around. Gave me a loaner on the spot without reservation... Someone called for a loaner when I brought the truck in and they were turned down.

MT Groove · April 14, 2017

Update on my truck. I took it in for the 4th time. This time I sent the service manager this link I found on this site

http://sandyblogs.com/techlink/?p=7170

He said we can try doing that. Apparently, they never got that bulletin? Took it in, they did the reprogram. Got it back the next day. For the first 90 miles or so, drove GREAT. Like the way it drove when I first test drove and took delivery. Then after 100 miles or so, back to harsh shifts and slight shuddering. I must say this is slightly better than before, but still the problem persists.

So, is there way way for the transmission to stop "learning?"

Jasadl · June 8, 2017

Hi All,

Quick Update: I did not get a large response for a class action suit. I did reach out to a few law firms who were not the least bit interested in pursuing a case against GM. (shocker)

On a positive note, the majority of the issues with my transmission went away on their own. It was a bit untimely as I was in the final stages of a BBB claim against GM that i had to withdraw. It still hunts for a gear every now and then, but the clunking / hard shifting only occurs once in a blue moon and no where near as harsh. So for those facing this issue, a little patience might be your best option. Started going away for me around 5k miles.

I did get a "transfer case control module reprogram" (says recall 28770 on the invoice) which I honestly don't know if that was what fixed it or not.

I also don't know if its related, but after the reprogram, I started noticing some sluggishness with the truck under certain conditions. It occurs when I'm driving at a constant speed or coasting and then attempt to accelerate (including out of turns). I have to press the accelerator a good deal to get the truck moving, otherwise it attempts to chug up to speed without downshifting. I can't say for sure if this is related to the transfer case reprogram because I put a borla on the truck around the same time. So it might have been doing this all along and I just didn't notice without the louder exhaust. There are a number or post on this site with possible causes and solutions to this (pedal flex fix, aggressive driving during relearn, speed booster, and the almighty tune). Working my way through these options now.

AgDoctor · June 8, 2017

Mine clunks and shutters. 8 speed.

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Eaglesfan1 · June 10, 2017

Update on my truck. I took it in for the 4th time. This time I sent the service manager this link I found on this site

http://sandyblogs.com/techlink/?p=7170

He said we can try doing that. Apparently, they never got that bulletin? Took it in, they did the reprogram. Got it back the next day. For the first 90 miles or so, drove GREAT. Like the way it drove when I first test drove and took delivery. Then after 100 miles or so, back to harsh shifts and slight shuddering. I must say this is slightly better than before, but still the problem persists.

So, is there way way for the transmission to stop "learning?"

Guys- new to the forum and scanned through the posts. I have the same issues with the trans at times hunting for a gear and slamming into a lower gear at different speeds. Seems to be mainly due to a change in grade combined with drive train lash which i expect some of this in a truck especially with the longer bed/driveshaft - but not this bad. ( i even recommended the truck to my next door neighbor and he bought a '16 exactly the same)

Have a '15 high country, crew cab, 6.2 with 8 speed and 6.2 bed, 22K miles. Honestly and ive been around cars and trucks my entire life this is the most disappointing trans i can remember. When i bought the truck i was thinking the 6.2 with the 8 speed is similar to the vette set up so it would give great performance and it really does when you just step on it from a stop the truck is bad ass and fast. The motor is strong and the trans shifts perfectly. Its on the fluctuating throttle or cruising conditions on the highway that i experience the really harsh clunking as it down shifts and even at times it does two harsh down shifts of confusion as i merge on to a highway almost completely killing momentum and then taking off. The above module is really helpful as i feel its a software issue and i will review this with the dealer but i cant see keeping the truck out of warranty and god help me i might need to look into a ford or ram....cant believe i just said that.

MT Groove · June 10, 2017

So for those facing this issue, a little patience might be your best option. Started going away for me around 5k miles.

Thanks for your response. Glad it worked out on your end. Unfortunately, on my truck, it is just as bad or worse now I've hit over 20k miles.

Honestly and ive been around cars and trucks my entire life this is the most disappointing trans i can remember.

Same thought here. I have owned many vehicles over the years, and this is by far the absolute worst transmission. It bothers me so much, especially considering how much this truck cost.

CounterMeasure · June 11, 2017

My in-laws where in town for a little over a week. Between the crappy shifting transmission and the lack of rear A/C vents in 90+ degree weather, I've had enough of this Denali. I've factory ordered a Ford Raptor. Now counting the days.

If I had the option, I'd drive this one through the front doors of GM HQ, throw the keys at the receptionist and say "its ya'll's problem now".

Colossus · June 11, 2017

It aint the receptionist's problem you don't like your truck! Don't spew your hatred at people who don't deserve it.

inspectorudy · June 12, 2017

Colossus, It's called frustration. When you fly and have a problem do you attack the flight attendant? Is it her problem? GM knows they have produced the worst transmission in their history but since it is a corporate mileage issue we are all screwed. They are not going to offer to reprogram because it will reflect on their mileage. They have lawyers by the hundreds so no, we are not going to sue them. I can tell you however, I will NEVER buy a GM truck again!

Strykkerhart · January 29, 2018

i Have a 2014 Sierra Denali 6spd with Multiple shift issues and clucks and bumps and bearing howling in the transfer case.

seems like most issues in these post i have taken it to multiple dealers and told no problem duplicated and works as intended.

i am tired of these issues and have been a gmc customer for life 2011 denal 6.2 and 2013 denali hd 6.6 all worked amazing which is why i purchased the 2014 6.2 6spd and it has been nothing but a dramatic difference.

i had 1 dealer kept my truck for a full month and when i got it back same issues and no duplication

find out to get the bearing howl to go away he turned the transfer case off auto and only the erratic cold shifting issues and clucnks and says it was no problems duplicated.

i am at my wits end and ready to make a change and all my family also.

by the way master certified tech for 22 yrs and never seen this kind of service and no one cares!!!

hutchman · April 3, 2018

Nate18211... I feel your pain. I just got my '16 Silverado 5.3 w/6 speed back from the dealer with my second 4-5-6 clutch hub failure. First time was about 14k, and second was at 24k. First time, they just replaced the hub. This time, they claimed they found excessive play in the clutches and were rebuilding the trans. Hopefully, it won't happen again, but I've not got a lot of faith. Haven't been able to drive it much, because the backup lights stuck on 3 days after I got it back. They had it for nearly a week to replace a corroded underhood junction block. Good luck with yours.

Hutch

f7firecat · April 4, 2018

On 4/10/2017 at 4:28 PM, 20feetup said:

I have a 2016 Sierra 5.3 6 speed with 9,000 miles. From the time I've bought it I've had issues with it finding a gear after coming down a hill. If I coast down a hill and then try to accelerate it will rev the engine like it is in neutral. Sometimes this will last until I'm under 20 mph's and then finally catch gear. Has anyone had this occur and if so have a solution?

I had this happen recently, I was in tow mode and had grade braking off, only thing I can think of that caused the issue90,000 miles on my 2014

03msc · April 11, 2018

So...scanning through some of these pages and pages of posts...is there a specific update I can request from the dealership for my '15? In other words, when I am taking it in for oil change and routine service next time, is there something specific I should tell them? An update or bulletin number, etc.?

I experience what I consider sluggish shifting, especially if I'm not accelerating hard (like slow take offs or in-city driving) and have seen more than one reference to an update that helped or fixed the problem.

Someone had linked to a TIS page to search for updates (I think) but when I put in my VIN it just gives me an error that essentially says I'm not authorized to view anything (no sign-in, of course, since I'm not a service tech).