2014 GMC Sierra 1500 Powertrain (other) Problems

I am experiencing ongoing issues with the 6L80E transmission that have significantly affected the performance and reliability of my vehicle. The transmission shifts harshly between gears, hesitates when accelerating, and occasionally slips before engaging. There is also a noticeable shudder during acceleration and inconsistent shifting, especially at lower speeds. These problems have become more frequent over time and raise concerns about the safety and dependability of the vehicle. The transmission does not operate as expected for normal driving conditions, and the issues negatively impact the overall driving experience. I am requesting a thorough inspection of the transmission, an explanation of the cause of these issues, and an appropriate repair or resolution to restore the vehicle to proper working condition.

NHTSA ID

11754615

Incident

Aug 3, 2026

The contact owns a 2014 GMC Sierra 1500. The contact stated that while driving downhill, the vehicle failed to accelerate as intended while depressing the accelerator pedal. In addition, the vehicle felt as if it were in neutral. The tachometer gauge revved up independently. No warning lights were illuminated. The contact pulled to the side of the road. The contact opened the front hood and noticed that one of the transmission lines had failed. The vehicle was towed to the residence. The contact replaced the hose and filled up the transmission reservoir. The contact stated that the failure persisted. The vehicle was taken to a specialty transmission place and rebuilt the transmission. The vehicle was repaired. The contact stated that a few months later the failure persisted. The vehicle was towed to the specialty shop, and the transmission was replaced. The contact stated that a few months later, while driving at an undisclosed speed, an abnormal odor was emitting from the front end of the vehicle. The contact was able to pull to a rest area, and when the front hood was open, the contact noticed that one of the transmission lines had a leak and transmission oil was being sprayed all over. The contact was able to replace the transmission hose. The manufacturer was not made aware of the failure. The failure mileage was unknown.

NHTSA ID

11736362

Incident

Nov 20, 2023

hard shifting transmission and fluid smells burnt, shifts hard in the lower gears and reverse

NHTSA ID

11691120

Incident

Sep 22, 2025

The contact owns a 2014 GMC Sierra 1500. The contact stated that while driving at various speeds, the vehicle was veering to the right or to the left and was moving upwards and downwards. Additionally, the contact stated that the vehicle was veering excessively to the left or to the right while turning. The vehicle was taken to an independent mechanic, where the front brakes were replaced, and the contact was informed that the sway bar end links were fractured due to rust. The contact stated that upon inspecting underneath the vehicle, the lower parts of the links had detached, and one of the links was flapping. The contact purchased new parts from the dealer, and the mechanic replaced the links. Additionally, the contact stated that the vehicle was experiencing hard shifts while driving from a complete stop and while coming to a stop. The vehicle was repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 67,000.

NHTSA ID

11676145

Incident

Apr 25, 2025

Mileage

67,000 mi

Truck completely shuts off at any speed going down the highway. Complete loss of power. Have to coast to side of road and restart vehicle.

NHTSA ID

11672901

Incident

Jul 11, 2025

Truck randomly shuts off and steering wheel locks up going down the road

NHTSA ID

11672478

Incident

Jul 10, 2025

Catastrophic transmission failure. Original transmission failed at 113,00 miles. I replaced it at the dealership with a factory rebuilt transmission and that transmission failed after only 40,000 miles. Now the vehicle is back in the dealership shop and they want me to replace the transmission a third time. This transmission is the 6L80 which is prone to fail, the torque converter fails and the transmission locks up I contacted General Motors and filed a complaint with them and they said they would not take any action or assist me with the repair.

NHTSA ID

11671482

Incident

Jun 12, 2025

Within the first week of buying my 2014 GMC 1500 SIERRA, the transmission fluid was black in griddy. I have had it flushed, then filter changed and new fluid put in within 2 week time frame. A week later had to put a new transmission in it. It barely would drive. So a purchase at 2,999 then to a transmission 4,800 and new control arm with ball joint with new axels. They were busted. Another 2,000. Its sicking. Advice

NHTSA ID

11669678

Incident

Jun 13, 2025

During a turn in the parking lot my vehicle would not allow me to turn something with traction control came up on the screen. The past few days the car got stuck at 0 rpms while driving and did not feel I had adequate power and other times has stalled.

NHTSA ID

11667320

Incident

Jun 1, 2025

The contact owns a 2014 GMC Sierra 1500. The contact stated that while driving on several occasions at speeds of approximately 35 MPH, the transmission shifted abnormally, and the vehicle started vibrating. Additionally, the contact stated that while driving at speeds of 65 MPH and higher, the failure worsened. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure. The failure mileage was approximately 146,000.

NHTSA ID

11662115

Incident

May 16, 2025

Mileage

146,000 mi

Transmission shutter, not shifting correctly. Had to replace transmission

NHTSA ID

11658923

Incident

Sep 17, 2024

I was driving around a lake with my family. We were fishing. I had no warning at all and my transmission started to sputter and jerk extremely bad and my brakes did not work at the same time. I had to use my parking break to stop my family and I from going into the lake at 40mph. I looked up on many websites and forums and saw multiple people with the same issue. I am afraid that this will happen to a young driver and it be very tragic. Please do a recall. My truck is still sitting at my house broken. I am on disability and can not afford to fix it. I just keep paying my payments with no use of my truck. Please I beg of you.

NHTSA ID

11656848

Incident

Apr 6, 2025

There is a torque converter recall on the 2014 GMC sierra 1500 however my vehicle was not included in the recall but my transmission / torque converter went out.

NHTSA ID

11635925

Incident

Jan 13, 2025

Failed transmission

NHTSA ID

11630406

Incident

Jul 10, 2024

A loud clunk is heard from the transmission when shifting from one gear to anther after having to reduce acceleration.

NHTSA ID

11597807

Incident

Jun 29, 2024

At slow speeds, multiple times, I have had the truck completely have an electrical failure and the engine shut off. I have replaced the negative battery cable and ensured all connections are good. This has happened on streets when turning and in parking lots. When this happens all of the screens in the truck flicker and the service stabilitrack light comes on and then everything goes out, to include the engine. Myself, my family, and other drivers have been out at risk when the truck completely shuts off on a street. The dealership has not been able to give me an answer. There are many forums online where the 2014-2018 year models of this and similar GM vehicles have had the same problem. We need a specific fix for this before someone gets seriously injured or killed.

NHTSA ID

11556617

Incident

Nov 24, 2023

Transmission lost power

NHTSA ID

11544570

Incident

Aug 17, 2022

Transmission problems

NHTSA ID

11531352

Incident

Jul 6, 2023

I am losing engine power. My OBD2 gives me P2138 and P0700 codes. I have changed the accelerator and knock sensors.

NHTSA ID

11517297

Incident

Apr 1, 2023

The contact owns a 2014 GMC Sierra 1500. The contact stated while driving 50 MPH, the transmission inadvertently shifted to neutral(N) and the vehicle stalled. No warning lights were illuminated. The contact related the failure to NHTSA Campaign Number: 14V374000 (Power Train). The vehicle was not diagnosed nor repaired by an independent mechanic or dealer. The manufacturer was made aware of the failure. The failure mileage was 112,000.

NHTSA ID

11512146

Incident

Mar 15, 2023

Mileage

112,000 mi

My lifters bent and my valves collapsed. I have had the vehicle repaired twice. No engine light warning. Also in Nov of 2022 oil is leaking into my cylinders. Common problem on several GM forums.

NHTSA ID

11508466

Incident

Aug 11, 2021

The contact owns a 2014 GMC Sierra 1500. The contact stated while his wife was driving approximately 65 MPH, the vehicle began to vibrate and made loud grinding sounds. The contact stated that the vehicle began to lose motive power. The contact's wife was able to exit the highway; however, the transmission was slipping out of gear. The contact stated no warning light was illuminated. The contact stated that the failure had become constant. The vehicle was not taken to a local dealer or independent mechanic to be diagnosed or repaired. The manufacturer had not been informed of the failure. The failure mileage was 94,302.

NHTSA ID

11501323

Incident

Dec 18, 2022

Mileage

94,302 mi

Going under 15mph, applying the brake causes the pedal to become stiff and lock up and not work. This has caused me to almost hit someone in traffic. I immediately got off the road and got my vehicle to a safe location off the road . Communicating with a dealer today to confirm possible recall issue or potential repairs.

NHTSA ID

11494516

Incident

Nov 22, 2022

My truck goes into “neutral” or doesn’t have power while driving at times and can cause a car crash.

NHTSA ID

11487126

Incident

Sep 23, 2022

My vehicle recently started "shuttering" while driving. Service report says it is a "common GMC issue with the Torque Converter", $3200. They also reported a "substantial leak" in the radiator, and again, says it is a very common fault of GMC Trucks. And another $2700. If these conditions are as common as they indicate, why are there no corrective measures?

NHTSA ID

11461441

Incident

Apr 1, 2022