What are some of the 2018 gmc sierra 6 speed transmission problems?

My sales man is fantastic and so are the people that work at gmc. I bought my husband his truck on July 2018 for his welcome home from deployment. Well we have had our truck almost 2 years truck has been in the shop for almost 3 weeks with a messed up transmission. Little did we know that the transmission only had 60000 mile warranty but if you buy a new one from gmc hmmm it has 3 years 100000 mile warranty. Well our truck has 72000 miles on it I know is a lot for the year of the truck but we took care of it and the Torque converter is the one that messed up and messed up the transmission. I called gmc the representative told me they had recalls on those torque converters hmmm we where never told about that i was also told the torque converter was still under warranty hmmm ?. Gmc has not been wanting to do anything about even though they know this year and model trucks have been having transmission issues for quite sometime but ignoring the issue. I have carshield it should I say car nightmare they do not want to fix it we have been waiting and waiting for them to do something and nothing. My husband is a disable veteran and has worked hard to have a nice truck and now we have no car no rental car because nobody wants to do anything and with hard times right now how the heck are we supposed to pay bills and a 6400 to get transmission fixed because gmc or car shield will not do anything for us. Can someone please tell me if they had the same issue with your truck we have a 2018 gmc 1500 Sierra. This is frustrating for me and my husband we still have to pay for a truck that is sitting at the shop and nobody will help us. I will never recommend anyone to get a gmc anymore and we have have referred plenty off people to gmc. My father in law has a truck also my friend has bought 2 already also. They have gave us the poor excuse I’m sorry your warranty has run out and we can’t do anything for you s**k it up pretty much and see if you can go get some money from the back yard tree smh. So no I will never refer gmc or carshield to anyone this has been a night mare for us for almost 3 weeks we are down the hole almost 900 on car rentals and what ever the shop is charging us to take transmission apart so the freaking warranty waste time and keep on giving us the run around for almost 3 weeks ????????. They ruined our Xmas for our kids and family. Someone if you had the same experience please leave a comment. I will keep leaving bad reviews anywhere I can until something gets done.I hope your truck don’t mess up good luck.

2018 gmc sierra with 65,000 miles on it and started doing the shutter on my transmission now

The 2018 gmc sierra 6 speed transmission has had reported problems from consumers such as transmission cooler line leak, harsh shifting, and transmission stuck in one gear.

I got a new battery now my transmission is not working will not shift

Transmission hit hard in 2nd gear. Came off the lot this way. Service man said it was learning my driving habits. Lol not happy with this truck.

Transmission issues hard shifting, jerking when shifting, hard to accelerate when at full stop

2018 GMC Sirra Transmission shutter

Same. My 2018 Sierra is sitting in the driveway, won't move because of the transmission. Very frustrating. Looking to join a class action lawsuit.

My 2018 has 45000 miles and now the transmission is shot. My truck has been babied since I have had it. Very very disappointed,spent to much money on this truck for it not to last more than 3 years

I believe that there’s hundreds maybe thousands of owners with the same Transmition problems and I was told by a mechanic at the Local dealership that it is a problem with the torque converter and it’s a factory problem from when it was built

Hard shift and shutters off and on at 39000 miles.

2018 GMC Sierra, 65k miles on it. Transmission shot. Driving from Pa to NC, 420 mile trip. Truck started to shutter and left me broke down on Rt17S. Had to have it towed to GMC dealer, they just (3/30/23) told me I need a new transmission, $7,100.00 dollars to repair. What choice do I have but to repair. I am going to join this class action suit. This is just not right.

My 2018 sierra is in the shop as we speak with 94000 kms on it having the transmission rebuilt as the torque convertor started to cause damage shith the shudder and hard shifting it did at times

My 2018 Yukon Xl 97k and shuddering and grinding on 11/10/23. Earlier this year transmission coolant line leaking dealership didn't say anything about know issues with these trucks. Truck started running hot in October 23, had the bypass valve installed and transmission fluid flushed, before this it wouldn't start so I had the battery changed. I faithfully had my oil changed and other maintenance done in timely manner. I contacted GM because this is known issue with these truck and was told they will only pay $741 out of 7k. As a faithful GM owner and a retirees daughter the way they are handling these things is a total slap in our faces. I never received a recall about these issues about my truck, I pay too much money every month to have to deal with the bs of GM

Same issues as all above. We all need to get together and slam this issue in Gm face and make them take care of an issue in which they are responsible for!

2018 GMC Yukon. 175,000 kms, did a transmission flush at a local dealer as I thought thsr would fix the hard shifting, no mention of a problem. A week later, transmission was really rough. Took it to a small town dealer, took the pan off and had meral shaving. Was advised it needs a new transmission. Currently awaiting one now, out of pocket. I had a 2002 Yukon Denali, 450,000 kms, no drive train issues....should have kept it. Losing faith in new GMC Yukons.

Same here. My confidence in GMC is pretty shaky at the moment.

Company pickup has 23000 miles on it 2018 gmc Sierra and it has the shimmy. Been there two weeks no answer

Cold weather killed my transmission don’t know what happened but you can hear the pump during gear shifts and now it won’t move when reaches certain temp

This is my 1st Gmc 2018 1500 Sierra 4x4 5.3 at 13200 miles, all I did is from places to place s and haul small stuff ,and now transmission Is going out, so I took into a shop at transmission service here in town, they told me it going cost me 6000. Thousand dollar to get it fix with a 3 year warranty on it, I know it Doesn't cost that much this is with at 170.00 in hrs.so that more.

Same problem shifts hard between 1st and 2nd then shutters reported may time was told I Had to learn how drive truck Ihave NEVER had a vehicle that did this somebody is not holding up there end GMC NOT GOOD CUSTOMER GUYS AT ALL

Same here my 2017 has 47k miles and Trans took a dump..torque converter and a few more parts good thing gmc covered it but what's next

I am experiencing the hard shifting at 80,000 miles. Combine this with AC, lifter and coil problems and you have paid the cost of replacing the vehicle. GMC really screwed the pooch at the consumers expense here! What puzzles me is that they knew about all this stuff and are somehow getting away with it!!!

Do it and if they knew it and just kept building the motherfukers

Harsh shifting 2018 gmc they aren't any good