February 1, 2016 at 7:37 pm #116749
I took delivery of a 2016 Sierra Denali (5.3 V8, 8-Spd, 3.42) in November and had to take it into the dealer a week later for a transmission issue (coming to a stop the truck would shudder as though the transmission was shifting hard into first gear or as though the engine was about to stall). 3 weeks after taking it into the shop, GMC engineers determined that there was a torque converter problem that was staying engaged too long causing the engine to nearly stalling out when coming to a stop. They okay’d replacing the entire transmission for a new one. I finally got the truck back (a MONTH after first taking it into the shop – and yes, the truck spent 30 days of its first 39 days of ownership in the hands of my dealer) and figured that would be the last of my problems. Since then, I’ve noticed that when yielding – or in traffic/congestion – when I’m slowing down almost to a stop (around 5 mph or lower), then stepping on the accelerator, there will be a long (1 to 2 seconds) delay between me stepping on the accelerator to move and the truck shifting into first and beginning to accelerate. I took it to the dealer again, and they claimed the delay and even “hard” little shifts are normal for this transmission because it is “adaptive” and constantly learning… What? I at first bought it (they are the pros), but I’m beginning to hate not having the confidence of pulling out of a driveway, side street, etc. and being able to immediately get the power and acceleration I need to get out of the way (or better yet to get on my way). Is anyone else here having similar issues with their new GM 8-spd?
February 10, 2016 at 1:18 pm #117903
The 8-sp is a pita for the first 10,000 miles of driving. IMO the problems are the voodoo GM computer programming.
There is another problem looming with the 8-sp; “Shake and shudder on Acceleration Excessive Engine RPM Fluctuation – (Jan 20, 2016)”, all 2015-2016 with 8-sp transmission.
Temp solution, double flush the trans, R & R the filter. If problem is not resolved the problem in internal to the torque converted and new one will be available soon.
If you are driving along between 30 and 65 mph and the vehicle shakes or shudders below 1600 rpms, you have this problem and it will not cure itself. The feeling is like driving over rumble strips on the road. ,
They were supposed to do the double flush, R&R the filter last Thursday on my truck. Has appointment and was talking with someone in the showroom when the SA came up and said, we cannot do it today. The parts dept does not have enough Dexron-HP in stock (only 5 qts) and they called around to 3 other dealers in the area and between them they could only come up with 13 qts of trans fluid, they figure 30 to do the job is adequate. Unbelievable!
Service Bulletin is PIP5337A
btw – I have a 2015 Sierra Denali 6.2L CC standard box 4wd.
February 11, 2016 at 8:10 pm #118429
First post. Hate to see you are having problems. Thought I might be the only one after hearing what service department is telling me. I just bought a 2016 Silverado LTZ with an eight speed and it shifts horrible. Love the truck but not fun to drive while taking off and stopping. Truck has 1400 miles on it because according to service department I have to get my truck to learn my driving habits. I am either a bad driver or have a truck with a learning disability. When truck sits over night or going home from work it always jerks a couple times taking off. Never fails. When I first bought, every time I would stop it would do something that felt like it was still shifting down when I should be stopped and actually feel like a double stop or surge forward. May sound crazy but really is the only way I can explain. There has been a couple times when I pulled into a parking spot to where it felt like I hit a curb because of the way it would stop. I have never experienced anything like this with any vehicle I have ever had. Seems like the computer is not in sync with the transmission at all. I will make turns and vehicle don’t seem to downshift when it should. I truly feel like I am driving a manual shift truck without using clutch. Love the truck and hope enough people speak up so this problem can be fixed. According to my service department vehicle runs as it should. If this is the case I wish I would have kept my perfect running 2013 Ford F-150 4×4.
February 25, 2016 at 3:21 am #121637
The dealer did the TSB (PIP5337A dated Jan. 22, 2016) double ATF flush and replace trans filter on my 2015 Sierra Denali 6.2L w/8-sp trans. Shudder is gone and has not returned in 1,000 miles. There is a new torque converter in the works to correct this condition. When it will be available is not known. You have to keep after the service dept in you dealer. Mine are great, they will do just about anything to please the customer.
Note – Replacing the trans for the shudder does no good because the same torque converter that causes the problem will come with the new transmission so nothing will be accomplished. Tell them to pull up that TSB. The dealers don;t commit every technical service bulletin (TSB) to memory and without an accurate description from the owner may not provide them enough information to search the data base for all issues. In other words, they give up to easily and start throwing parts at it such as a new transmission.
July 20, 2016 at 8:16 am #133650
I purchased a 2016 Yukon Denali in Jan. 2016. It will set in the carport for several days sometime before it is driven. When it sets there for 48 + hours and I drive it, it will back out of the driveway ok, but when I try to accelerate it will pause for 1 -2 seconds, then will pickup and run properly. Runs great until I let it set for the 48+ hours. The first time I called a service manager about this, he said GM had a fix already, but the would have to go into the trans. and replace a “plate”. I told him I would drive it like it is for a while, (my mistake)!
I’ve decided that’s too much to spend on a vehicle with a faulty trans., called him again, left it with them 5 days. “can’t fix it, can’t get it to show the problem” Sent it home, problem still there!! Anyone else having this problem, if so did you get it fixed?
November 15, 2016 at 4:07 am #144432
I purchased a 2015 Sierra SLT with 6.2l and 8 Speed in August 2015 and when it is cold meaning its been setting a day or so, you will almost always get a slip in the transmission causing a several second delay. I had went to a show for my company in Atlanta GA and almost got hit because, I backed out onto the street and when I put it in forward it would not go for several seconds because it just revs up the stairs shudders going forward. I have taken it back to my dealer twice and they cannot recreate the problem so, they have done nothing. I ran into a man at my dealership who was in the process of describing the exact same problem and gave him my business card to see if they fixed his issue. The dealership told him the same thing and he called me yesterday to let me know he and his wife got hit in the Highland NC because, he backed out and could not go forward just like I do weekly in mine. I now have a couple phone videos of mine doing it to show my dealer again but, I am wondering what to do as they have not done anything yet.
August 7, 2016 at 6:17 pm #135441
I’m not experiencing a shudder at speed, only when downshifting into first (when doing a stop and go). I notice it is much more apparent when I first turn the vehicle on after the powertrain has cooled down. My current “work around” is starting it up, putting it into Tow/Haul mode, and driving off. Because it forces to hold first longer and down shift faster, there isn’t a lag or shudder… but fuel economy suffers.
December 5, 2016 at 11:07 am #146075
I just bought a 2017 silverado ltz 6.2/8-speed and I’m experiencing similar issues! If I’m driving 35-55mph every once in a while I get a shudder in the wheel for a brief 1-3sec on and off while I’m at these speeds it’s so frustrating!! The truck has 500 miles on it and my old 1995 silverado with 185k drove with no shudder or vibration issues.
December 5, 2016 at 12:30 pm #146097
I purchased a 2017 GMC Sierra 5.3 with the 8 speed transmission two weeks ago. (This is my 5th GMC truck) no previous problems.
I now have 1000 miles on this truck.
I noticed the truck shudders and seems to have a hesitation between gears, especially at low end. I went in on Dec 2nd 2016 and talked with the dealer who said it takes a while for the transmission to learn my driving habits. What? . It also clunks when taking off. Was told the clunk is normal. This morning Dec 5th i warmed the truck up for ten minutes put it in reverse and the truck would not move. just revved up. 10 seconds later it slowly starts to back up onto the street. I put it in drive and it still won’t go ,just reeves up for another 10 seconds before it finally jumps into gear. Made an appointment to bring it back to the dealer.
This can not be normal for a commercial grade pickup.
December 5, 2016 at 1:29 pm #146105
Mine has clunks every once in awhile but has never slipped like yours, I have yet to take it in the dealer ship, Ive literally only owned the vehicle for 12 days and was so pumped to have a 6.2l truck and now this!!! I paid 60k for the truck and it has a shudder while driving. I can definitely tell its in the driveline and I believe its the trans, Watch your rpm cluster because when I’m on cruise at say 45mph it can’t seem to make up its mind and goes from 1000-1200rpm constantly. My truck does not have a constant shake like the other “Chevy Shake” videos. I only notice it on smooth roads and it drives me nuts. If i take it in I believe they will say there is nothing wrong or in the same case as you say its “Learning”. This is very very frustrating, makes me wonder if my trans will start slipping like yours….
December 5, 2016 at 1:31 pm #146106
By the way my truck is a crew cab short box, when I search issues online all the trucks that comes up are in this configuration.
December 6, 2016 at 9:18 am #146188
Thank you, Ill be curious is to what they say. I started another topic on this issue and got a response from an individual that works at a Cadillac dealer, He said that many of our same complaints are also being brought up there and they have been either replacing transmissions or torque converters to solve the issue….
December 6, 2016 at 6:20 pm #146244
I have a ’17 Denali with less than 500 miles that’s experiencing something similar. If I’m cruising between 35-60mph and I lightly press the gas to maintain speed, I get a violent shudder. I also observe the tachometer bouncing like crazy when this happens.
December 6, 2016 at 6:45 pm #146251
That is what mine does, The service rep tried telling me it could be the V4 to V8 but it’s not! The torque convertor is acting up definitely. I’ve noticed lately 50mph does it the worst for me, but as soon as I either lay into it or brake it goes right away…If I launch from 0-70 it shifts perfectly but if I hover around 50 then slow down to 45 and then speed back up I start to get a shudder in my wheel and sometimes I feel it in the pedals as well.
December 19, 2016 at 9:50 am #147288
I bought it brand new Dec 2015 (2015 High Country 4×4, 6.2ltr V-8) with the new eight-speed Hydra-Matic 8L90 transmission. So I’ve had it a year now and have put 19k + miles it. I noticed about a month ago when the engine was cold and I went from park to drive it felt as if I was parked on a hill and the trans was in a bind, taken 1-2 seconds before roughly engaging in gear. Then it started doing it more often even when the transmission fluid temp was above 130. Well last week it began to shudder almost like driving over road strips before a stop sign. I also noticed that if I had it on cruise control between 40-60mph the tachometer would rev up every time it shuttered/vibrated. It took it back to the dealership as it is still under warranty and had the mechanic ride with me so he could see for himself what my Chevrolet was doing. He knew immediately as to what he thought was causing the vibration…torque converter he says! So as of right now it is in the shop to replace the torque converter with an upgraded one per this bulletin 15389 which provides a service procedure to reprogram the transmission control module (TCM) on certain 2015 model year Cadillac Escalade, Escalade ESV, Chevrolet Silverado, GMC Sierra, Yukon Denali and Yukon Denali XL vehicles equipped with an 8L90 8-Speed (M5U) transmission and 6.2L (L86) engine. These vehicles may have a condition in which transmission calibration allows a higher than target energy input to the torque converter clutch (TCC) under certain conditions. This may lead to faster than expected torque converter clutch material wear, and a shudder feeling.
December 29, 2016 at 1:04 pm #147993
You are not going to like to hear this but this is normal and yes you have an adaptive transmission computer that is constantly adjusting to the way its being driven. You can take it back to the dealer all you want but nothing it going to change as the dealers have no fixes. Its the way the new computerized vehicles operate. It will get better as the miles roll up, give it 20,000-30,000 miles and you will adapt, I did.
2015 Sierra Denali 6.2L 8L90 Crew Cab Standard Box 4WD
February 20, 2017 at 12:10 pm #152614
Before searching for answers, I thought I would have to accept what I was being told about the “adaptive transmission”. I experience most if not all of the issues above, most of the time. Although it brings me no comfort to know others are suffering with the same issue, it is good to know it is not me. So much so that after only 2000km, I am looking forward to an opportunity to get rid of this truck. Had I known when test driving it, or had I been told this would be an on going issue, I WOULD NEVER have purchased it. Unacceptable. As a Past Silverado owner, loved every time I got behind the wheel, now seconds after putting that thing in drive it is like a nothing I have ever experienced, constant shudders, jerks, lugging and jumping. all I can hope now is that someday, a fix will come out, that and I hope the service Dept doesn’t hide when the seem me coming every week. A real shame because I was so looking forward to this truck and now I can’t stand to drive it
April 8, 2017 at 6:50 pm #159600
I bought my 2016 High Country in August 2016, I am experiencing shifting problems from 1st to 2nd gear and sometimes makes an awful clunking noise. I am going to take it into the dealership on Monday to see what they are going to tell me, but by the sound of it, it doesn’t sound like they are going to do anything. Had I known this before I purchased the vehicle, I would never have bought it. I only have 7000 km on it.
April 13, 2017 at 4:39 am #159911
Clunking is a normal characteristic of GM 6 and 8 speed transmission. Its all computer BS programming to achieve fuel economy. That’s all the matters when building these trucks, make them as fuel efficient as possible even though they may drive like crap. Your driving a computer program.
Mine (15 Denali) still clunks (8-sp) after 35,000 miles. A good friend is in service management at GMC/Buick/Cadillac Dealer. We were talking a few months back about the clunking and he commented, if I had a $ for every customer complaint about clunking, I would be a rich man. Its the way they are.
June 20, 2017 at 11:14 am #165625
Hi everyone, I just bought a GMC Sierra all terrain x package, I am in love with the truck but sometime when the gear changes from 1 to 2nd it’s gives jerk with clunking noise , I took it to the dealership with 98kms on it, I was told that’s the way a truck shifts. Now with 1200kms it still drives the same, it gives jerk while shifting . Reading to the post above that a truck learns to your driving habits.. I think my truck has poor learning abilities. My friend bought the same truck one year ago and it runs smoother than mine.. I hope GMC should resolve this problem.
September 8, 2017 at 5:43 pm #172314
Same shudder issue here!! 2015 Yukon XL Denali with the 6.2L 8spd tranns – with 30,000 miles. I do have a slight .5 sec delay when shift from part to R or D especially when cold. But my main issue is the shudder I am getting a drastic vibration when my RPMs range between 1300 and 1700. Mainly between 45-55mph.
Once I get above that the shudder goes away. to keep this from happening i have to drive in Manual gear 7 so the R’s stay above 1800.
I have had the transmission fluid checked, Mass Air flow sensor replaced, new plugs, and now my dealer wants to replace the exhaust pressure value for the tune of $900.
I have been dealing with this shudder since i bought it with 10K miles.
this is the first time I have ever heard anyone talk of a torque converter issue. I may have to spend the $350 and get the double tranny flush with the new filter. Hopefully this will resolve my issue. has anyone else had good lock with the tranny flush method other than Z15?
November 15, 2017 at 12:25 pm #180517
Good day to you all. I have a 2016 Sierra with the 8 speed transmission. At 18300 miles I took the local dealer because of a vibration at low RPM throughout the gear range; rough idle; and jerking gear changes from 1st to 2nd at low speeds.
The dealer had the truck for 5 days. They had to await the back-ordered tranny flush juice. They did the “triple flush” of the tranny and also replaced all 4 engine mounts. They claimed they updated the software on the truck engine management control and they also updated the software on the infotainment system.
I now have 19300 miles on the truck, and it is now going back for the exact same reasons – rough idle (not as bad as the first time), and the start of the vibrations.
I expect them to keep the truck for a week, as I dont wish to continue going back there every 6-8 weeks.
I was advised that they are short handed WRT transmission specialists. This is a common excuse in Fort Lauderdale, with at least 5 dealers all “sharing” the same transmission specialists.
My humble advise is to have them do the tranny flush and confirm there is a warranty on these services. I assume the flush is good for +- 1500 miles MAXIMUM.
As soon as I have my truck back, i shall report the dealers explanation.
November 21, 2017 at 7:55 am #180984
I just bought a CPO 2015 Sierra Denali with 6.2L 8-speed that was having the shuddering issues at 2nd and 3rd gear. The shuddering was so bad at 45-50mph that the entire dash and steering column shook like it was possessed. Took it to a local dealership and they replaced the torque converter. The truck is no longer having the issue. Rebuilding the transmission is not going to fix the problem. Ask that they specifically check the codes for the torque converter.
December 11, 2017 at 6:59 am #255160
Update on my 2016 GMC Sierra transmission problems:
I picked up my truck 2 days ago from my dealer. I had to wait 2 weeks for get the part for the truck. It was a new torque converter.
There were reportedly 2 versions of the converter. The first one was not working well, so they made a new one.
The part number installed in my truck is: 24286975 – Description: Converter 4.115
The “core return” part number is the same number as above.
I now have 19400 miles on the truck. If this does not fix the issue, i am going to research for a good lawyer to look at this case.
Updates to follow on the GMC Parkinsons Syndrome.
December 12, 2017 at 9:08 am #258845
I bought a 17 Denali 6.2 w/ 8-spd in march of 17. I finally got around to taking to the dealer for a shifting issue from first to second gear (19k miles). If I was accelerating slowly it would shift very hard into second. It appeared as though the RPMs would go too high before shifting, then slam in to second. They replaced my transmission, and now I have a whole new set of problems. Its sluggish and hesitant between gear 1-3 or maybe 1-4 when accelerating, and sometimes clunks into first coming from second upon stopping. Needless to say I’m on the verge of trading it in.
January 14, 2018 at 2:08 pm #371674
New to the forum
I have carefully read all of the transmission posts
I have a 2016 Sierra Crew Cab. I love this truck….design and finish.
I have experienced all of the same problems mentioned in this forum.
I complained to the GM Executive Office and they responded immediately!
They put a new tranny in my truck….same issues.
Ultimate answer is that this the new normal in technology with the idea that the
Tranny will adapt to owner’s driving habits
That is BS….Traded in a perfectly wonderful 2011 Sierra for this truck.
My wife’s 2012 Suburban with a 6 speed operates smooth as butter.
My Question…do the 2018 Sierras have this same issue ?
January 28, 2018 at 5:20 am #400829
All is the same for the 2018 Sierra 1500, sad to say..
February 16, 2018 at 6:49 pm #433920
So I’ve been following this post for sometime…I have a 2016 GMC Sierra All terrain with 8speed auto and have had similar issues. Trans would jerk coming to a stop, clunks, shakes and shutters 30-60mph, lost power during acceleration, and I may have found a fix. I had it in the dealership many times, they said “this is normal”. Obviously it wasn’t. I got frustrated, called GM lemon law and they got involved with my case. Did the trans update, didn’t fix anything…. Maybe got worse to be honest. Then after fighting for a few weeks and few dealership visits they decided to take the truck in for a full assessment. After 2 days my truck was done. They replaced my valve body in my trans, apparently some of them had issues from factory. Did the valve body, and flushed the trans…haven’t had a problem since. Strong mid range power, shifts smoother, and no more jerks or clunks (so far). For all of you who are experiencing the same issues I had, give the valve body a shot. It controls shifting in your trans, and correct torque engagement. Dealership put mine in in 2 days. Love the truck again!
March 12, 2018 at 5:39 pm #471202
2016 Sierra with 8,500 miles. got the tow package/6.2 with A8 tranny. Truck is loaded and extremely quiet, but every now and then clunks into gear to the point where it annoys the sh#t out of me. Did I mention the truck handles like a Tug Boat. I do like the truck and can forgive the handling but not the clunking…
March 22, 2018 at 1:11 pm #482521
Ditto on having hard shifting issues issues with the 8-speed in my 2017 Sierra SLT. Im trying to work it through GMC now. Dealar has given up.
March 22, 2018 at 1:14 pm #482526
HEY LAGO13D! Can you give us anymore information the transmission fix you got? Is it still working out?
Is there any other information I need to communicate to mechanics, besides it just the valve body? Thanks!
March 22, 2018 at 1:35 pm #482554
Surly,. My dealership did a transmission flush and replaced the valve body in the transmission itself. They then reprogrammed and updated the transmission. The truck has been shifting a lot better, I’m not saying it’s perfect, but it doesn’t jerk when I come to a stop anymore. When your on a hill it still has some banging issues, but that’s only when you slowly come up a hill then go to accelerate. It’s a problem that nothing is going to fix in my opinion. I just want everyone to know that I have a K&N cold air intake on my truck and that itself helped a lot with the hesitation issues. I called GM lemon law on my truck and got GM corporate involved and it forced the dealership to make moves. I have learned that you cannot rely only on the dealership text you have to have GM involved because they definitely want to make sure you have a good experience.
March 22, 2018 at 1:38 pm #482561
I hope I gave some good insight, I was sick of going to the dealership every two weeks and this last go around it seem to do a lot to my truck. To be honest the eight speeds are just terrible Transmissions. They’re not programmed correctly and personally I think the torque converters are wrong as well. But all of the issues I was having prior to the valve body replacement have reduced dramatically if not been completely eliminated.
Hope this has good insight for all of you,. I’m putting a cat back dual exhaust on it now and we’ll see if that affects anything
April 11, 2018 at 3:52 am #489909
I have the same issue with my 2016 Sierra 4×4 I have had them look at it in the shop for over a year. Initially I thought it was just a quirk, But it never went away. The Service managers just seem to throw their hands up and said that is the way it is. I now have 38K on the truck and still same issue. I am concerned that when the drive train warranty runs out I will be without a transmission.
1; Told to wait till temperature in truck warms up. In winter that is 15 minutes of idling in the driveway.
2: vehicle clunks going into gear if not 100% warmed up
3; Once in a while, vehicle hesitates going around corner from a start, This is annoying as is or could be a safety hazard.
4; Clunk once in a while while even warmed up.
Of course, it seems that these cannot be duplicated at the shop.
I have owned trucks for over 40 years Never had this issue in the past, if we did , then the transmission was in need of service.
Who at GM do I have to talk to?
April 12, 2018 at 5:06 am #490096
Good luck finding anyone to listen to you at GM. I am honestly getting pretty sick of driving my 2014 SLE Z-71. I hear the 8-speed is worse than my 6-speed, but that’s hard to believe. The truck alternates between lurching, lugging, and clunking throughout my entire commute. I swear the engine and transmission are independently controlled by drunken monkeys who are mad at each other. After denying any knowledge of the issue for two years, the service manager at my local dealership finally said the jerky drivetrain is their number one complaint. He claims it doesn’t harm the drivetrain, but I have trouble believing that. There are times I actually believe I will see parts bouncing down the road behind me. We have five vehicles in our family (1991-2015) and no other vehicle drives as poorly as the truck. I drive many rental cars per year and only one has been worse in the past few years. I just wish the dealership could reset the system to the way it was when I bought the truck new. They have tried pulling the battery but it doesn’t help. Had I not purchased an extended warranty, this truck would have been gone by the time the factory warranty expired. As it is, I will get rid of it before the extended warranty expires. I made the mistake of holding onto my last vehicle (Tahoe) too long–the Castech heads cracked at 100k miles (Mobil-1 at 4-5k intervals) and the 4L60E transmission developed a flare at 120k miles (fluid changes at 30k intervals). I certainly don’t have any faith that my GMC will do any better.
April 12, 2018 at 9:09 am #490141
Gm lemon law….
Contact Us Via Email
Contact Us Via Phone
Monday to Saturday
8 a.m. to 9 p.m. EST
That’s who I spoke with and they communicated directly with my dealer to make sure the problem was fixed and once they got involved my truck got the new valve body and a new transmission update and haven’t had any problems since.
In some cases they replace transmissions for people but they have to go through their step so I would start there for all of you who have issues
June 1, 2018 at 8:40 am #495975
Hi all – Here’s an update on my experience dealing with GM and the dealer with “the clunk” issue on my 2017 Sierra SLT.
Ive been dealing with a GM executive office person who is assigned to you when you contact them about issues. Long story short they were helpful in pressuring the dealer to do another ride test on my truck. I had done a ride test with them before, but as many have experienced, the vehicle decided not to have problems during the test, so they claimed there was nothing wrong. (Note – 5 months earlier they had experienced a problem and did a refresh on the tranny which initially worked for about 1000 miles. After a few thousand miles more of experience the problem again the dealer apparently got tired of dealing with me and decided to forget they had seen the issue AND forget that they had told me they had seen the issue with other customers.) Hence the need to get GM to pressure them to look at the problem again. Fun.
NOTE: When you deal with GM directly, although helpful in managing the process, they will label this issue as a “Characteristic of the vehicle” and therefore ineligible for any kind of buyback. So now you know the obvious, widely reported defects in GM 8L90 and 8L45 transmission are actually built in “features” that you should be happy about after spend $60k! Professional Grade Baby!
So just had another ride test where the tech plugged in a computer and we went for a long drive. We did experience the “clunk” and the tech acknowledge the issue in general with other vehicles. He said that they had tried to get direction from GM regional techs on how to fix, but no help was forthcoming. We identified the main issue as a “learning problem” impacting deceleration from 3rd to 1st gear. The tech recommended I bring the truck back in and he will try to modify (relearn) the software shifting to remedy that, based on the ride data picked up during the test drive. Ill report back here with results.
July 19, 2018 at 9:18 am #499604
@swebber99, any update? I have the same truck and SAME issue as you! To a TEE! I’m anxious to hear back from you!
The 3-1 CLUNKY downshift is driving me CRAZY. It literally surges my truck forward most of the time, and I’m starting to hate driving this POS.
- This reply was modified 1 month ago by wlezel.
July 19, 2018 at 9:44 am #499610
2 months later update after GM tech “smoothed” my 3-1 tranny gearing..
Still clunking, but now its more pronounced in the 1-2 gear change. GM wont do a thing. Still “a characteristic of the vehicle”.
The dealer tech now acknowledges the issue and have really tried to get info from GM regional techs, but they wont help.
He thinks they just don’t have a solution and dont know what to do so they are being tight lipped.
The big question is will the clunking wear out drive train components over time. I cant imagine it it wont, give the noise and the occasional violent nature of the clunking.
Im considering dumping the truck or trading in for another brand.
I am (was) a loyal GMC owner over 25 years owning 3 trucks. I think I may be done.
July 19, 2018 at 9:26 am #499606
Update on my end.. bought a bulldog tuner, 99% clunk free and well worth it !
July 19, 2018 at 9:37 am #499609
July 19, 2018 at 9:28 am #499608
July 19, 2018 at 9:58 am #499611
After the triple flush and recalibration about 8,000 miles ago my truck has started shuddering again. The 2-3 upshift is very rough and cruising at about 50mph and lightly applying throttle to maintain speed feels like you’re driving over the rumble strips. Sometimes it will even shake quarters out of my cup holder. A couple thousand miles ago I took it in and got the normal operation BS story. It’s going back again shortly.
Has anyone ever braked really hard (but not came tona stop) then tried to accelerate quickly? Mine has dropped out of gear doing this.
August 16, 2018 at 6:51 am #502974
I purchased a pre-owned 2017 GMC Z71 with the 6.2 and 8spd in April this year. It had 10,500 miles on it at the time and I really like/liked the truck. Great power, fuel economy and very comfortable. Last moth while traveling on the interstate (on vacation 250 miles from home) it started exhibiting the same problems mentioned above (like someone flipped a switch). At first I thought I was riding on rumble strips and tried swapping lanes, no change. Next I noticed the engine RPM’s were fluctuating and it felt like it was hunting for the right gear. It also exhibited the same problem mentioned in another post above when going uphill. We were not towing anything, the hitch had never been used when I purchased the truck and I have not pulled anything heavier then our 16ft boat. The truck had 16,700 miles on it when this started. Once we arrived at our vacation destination I did a search to see if other people had been experiencing problems with these transmissions and after viewing all the post I wished I had done more research before purchasing this truck.
I was finally able to get it to the dealership and left it with them on August 6th. They still have it and can not correct the problem. They did the flush and replaced the engine mounts. They also commented that they know there are problems with this transmission. I was told yesterday that they are trying to contact GM to see what to do next. I have purchased 6 new GM vehicles over the years and 7 pre-owned GM vehicles and never experienced anything like this before with them where the problem couldn’t be corrected. If they don’t get this corrected I will be done with GM.
August 16, 2018 at 2:52 pm #503039
Let me be the FIRST to congratulate you on driving or owning your last GM vehicle.
I have 30k miles on my 2016 Sierra – 4×4 – 5.3 and “chinese-like quality” 8 spd tranny. While driving at low speeds, and when the gearbox changes gears, it give me the “GM-Wake up” jolt, as I now refer to this incident. I have given up on complaining, and now accept the fact that I have been ana–ly abused by GM on this purchase. When I purchased this truck, a kiss, or a nibble on the neck, from the GM salesman, would have made me feel a little better today.
I had thought I would have this truck to pass down to my great grand kids, but sadly, this will not be the case. I am now looking forward to my future truck go-to brand: Anything But GM.
Good luck, sailor. You too shall one day find acceptance is the way to go. Namaste.
August 21, 2018 at 9:15 am #503458
The dealership called Friday (August 17th) and stated they had the problems resolved. I picked the truck up around noon and initially it performed great. After about 40 miles of driving I made a stop and upon starting the truck the shudder came back while idling as well as the rpm fluctuations. At highway speeds the shudder comes and goes and a couple of times it acted like it was hunting for the right gear which was one of the problems it had before the repair attempt. I contacted the dealership and they stated they would look further into the issue. If the TCM is really “learning” my driving habits then I will have to agree with an earlier post that the computer has a learning disability.
After a couple more days of driving the truck it is starting to look like all of the original issues may be returning.
I will say the dealership has been very cooperative and wants to resolve the problem. They even picked up the extra cost of the rental beyond what GM covers.
I have also contacted GM priority care. Below is their response and I will keep posting updates.
“We understand how you like to have this issue resolved and we would like to work closely with you along with the GMC dealership in resolving this issue. Due to the nature of your concern we will endorse your case to a Senior Advisor who will continue to work directly with you and your dealership to review your vehicle and concerns. Please know that all the information you have provided will be available to both your dealer and Senior Advisor as well. We will forward your case to them and the Advisor and Dealer will review your case and vehicle details, and one of them will be in contact you within 2 business days to assist you further.”
You must be logged in to reply to this topic.