What year did GM fix the 8 speed transmission?

General Motors (GM) has addressed the long-standing issues with its 8-speed automatic transmission in 2021, providing a solution for affected vehicle owners. The 8-speed transmission, which was introduced in various GM models starting in 2015, had been plagued by problems such as harsh shifting, delayed engagement, and unexpected acceleration.

The 8-Speed Transmission Problems

The 8-speed automatic transmission, developed by GM in partnership with Ford, was intended to improve fuel efficiency and performance in a wide range of GM vehicles, including the Chevrolet Silverado, GMC Sierra, Cadillac Escalade, and others. However, the transmission quickly gained a reputation for reliability issues, with many owners reporting problems such as:

• Harsh, jerky shifting


• Delayed or sluggish engagement when accelerating from a stop


• Unexpected surges of acceleration, often referred to as "torque converter shudder"


• Premature wear and failure of transmission components

These issues led to numerous customer complaints, warranty claims, and even lawsuits against GM, as the problems posed a safety risk and caused significant frustration for affected vehicle owners.

GM's Solution and Recall

In 2021, GM finally addressed the 8-speed transmission issues by issuing a recall and implementing a comprehensive solution. The automaker worked with its transmission supplier to develop a software update that addressed the root causes of the problems, including:

• Recalibrating the transmission control module to improve shift quality and responsiveness


• Updating the torque converter control logic to reduce shudder and vibration


• Implementing enhanced diagnostic capabilities to better detect and address potential issues

The software update was made available to all affected vehicle owners through GM dealerships, and the company also extended the warranty coverage for the 8-speed transmission to help address any lingering issues.

Improved Reliability and Customer Satisfaction

Since the implementation of the 8-speed transmission fix in 2021, GM has reported a significant reduction in customer complaints and warranty claims related to the problematic transmission. Owners of affected vehicles have also reported improved driving experiences, with smoother shifting, better responsiveness, and a reduction in the previously experienced issues.

The successful resolution of the 8-speed transmission problems has helped to restore customer confidence in GM's engineering and quality control, and the company has been able to move forward with the continued development and deployment of its advanced transmission technologies.

When did GM start using 10-speed transmission?

GM started using its 10-speed transmission in the 2017 model year, with the first application being the Chevrolet Camaro ZL1. The 10-speed transmission was then introduced to a wider range of vehicles, including the 2018 Chevrolet Tahoe and other models, with a company-wide goal to have it in eight vehicle models by 2018.
 

• Initial application: The 2017 Chevrolet Camaro ZL1 was the first vehicle to use GM's 10-speed transmission. 
• Wider rollout: GM announced in March 2016 that it would roll out the 10-speed transmission across eight vehicle models by the 2018 model year. 
• 2018 models: The 10-speed automatic transmission became available in other vehicles for the 2018 model year, such as the Chevrolet Tahoe with the Performance Package. 

What year are GM 8-speed transmission problems?

GM 8-speed transmission problems primarily affect vehicles manufactured between 2015 and 2019, with specific models of Chevrolet, Cadillac, and GMC trucks, SUVs, and sports cars being most affected. The issues reported include shuddering, lurching, hesitation, and harsh shifting, and the problems are linked to the 8L45 and 8L90 transmissions. A major cause was reportedly the original transmission fluid, which was later replaced in some vehicles, and the company has issued numerous technical service bulletins to address the shifting complaints. 
Affected vehicles

• Chevrolet: 2015-2019 Silverado, 2017-2019 Colorado, 2015-2019 Corvette, and 2016-2019 Camaro 
• Cadillac: 2015-2017 Escalade, 2016-2019 ATS, 2016-2019 ATS-V, and 2016-2019 CTS (excluding V-Sport) 
• GMC: 2015-2019 Sierra and 2017-2019 Canyon 

Reported problems
Sudden lurching or shuddering, Significant delays in acceleration or deceleration, Hard shifts or harsh engagement, and Hesitation followed by a clunk or shake. 
Potential causes and solutions

• Faulty transmission fluid: The original fluid was found to be problematic, causing torque converter issues. A new fluid was later introduced to fix this for many vehicles, says Reddit users. 
• Technical Service Bulletins (TSBs): GM has issued numerous TSBs to address these issues, and one solution involved changing the transmission fluid and a customer satisfaction program was implemented to replace some transmissions. 

Legal action

• Multiple class-action lawsuits have been filed against GM over these transmission issues, involving vehicles from 2015-2019 and later models. 

Is the GM 8-speed or 10-speed better?

The GM 10-speed is generally better for acceleration and towing due to its wider gear ratio spread, while the 8-speed can offer better fuel efficiency and some models are considered more reliable. The "better" choice depends on priorities: the 10-speed provides superior performance, but the 8-speed is a viable option, particularly for drivers prioritizing long-term reliability or who may not need the extra gears for heavy-duty use. 
10-speed advantage

• Performance: The 10-speed's wider overall ratio spread and smaller steps between gears can lead to better acceleration.
• Towing: It offers a lower and higher gear range, which is beneficial for towing and climbing.
• Efficiency: It can provide improved fuel economy on the highway by allowing the engine to run at lower RPMs. 

8-speed advantage

• Fuel efficiency: In some tests, the 8-speed has shown better fuel economy, especially when compared to a 10-speed in a less aerodynamic vehicle like a truck with a lift kit. 
• Reliability: Some 8-speed models are considered more reliable, and issues like torque converter shudder can sometimes be fixed by changing the fluid. 
• Simplicity: With fewer gears, the 8-speed transmission may be simpler and have fewer components that can potentially fail. 

Which one to choose

• Choose the 10-speed if: You prioritize acceleration and towing performance above all else and don't mind the potential for more shifting.
• Choose the 8-speed if: You are looking for a balance between performance and fuel efficiency or have concerns about long-term reliability. 

What year did GM put 8-speed transmission?

GM started using its first 8-speed automatic transmission in 2014, with the 8L90 model, which debuted in the Cadillac ATS and was also used in the Chevrolet Silverado and Corvette. The 8L45, a lighter-duty version, was introduced later in 2016. 

• 2014: GM's 8L90 8-speed automatic transmission first appeared in the Cadillac ATS and was also used in the Corvette and Silverado pickup trucks. 
• 2015: The 8L90 became more widespread, appearing in a greater number of vehicles like the GMC Sierra, Yukon Denali, and other trucks and SUVs. 
• 2016: The lighter-duty 8L45 transmission was introduced for use in applications with V6 engines, such as in the Chevy Colorado and Camaro, and the Cadillac CT6.