What are the Most Common GM 6 Speed Transmission Problems? (7+ Expert Solutions)

In this brief guide, we are going to provide you with common problems with GM 6 speed transmission and what you can do to rectify these problems before they worsen.

GM 6 speed is an automatic transmission and does not require any manual input to shift gears while driving as most of the cars have automatic transmission. Various sensors and mechatronic systems work in coordination to shift gears automatically. 

Automatic transmissions have a global reputation for quality, reliability and durability. However, there are many problem with automatic transmissions and we’ll tell you why and how you can solve them

What are the common problems with GM 6 speed transmission?

Some of the most common problems with GM 6 speed transmission are:

  • Grinding or clunking noise
  • Transmission fluid leakage
  • Shaking and shuddering 
  • Transmission Slippage
  • Burning smell

Why is Grinding or clunking noise a problem with GM 6 speed transmissions?

These GM 6 speed transmissions are not manufactured to make such grinding or clunking noises and if you are hearing such unpleasant noises while driving then you should check with your mechanic as this might get a serious damping issue.

What are the signs of this problem with the GM 6 speed transmission?

You will hear these noises while driving and will be very unpleasant to your ears which can be taken as a sign that the transmission is having some problem.

How to solve this GM 6 speed transmission problem?

Normally this sound means that a component within the assembly needs to be replaced as it might be fractured. The entire assembly from which the sound is coming must be removed and rebuilt to fix this problem.

Why is Transmission fluid leakage a problem with GM 6 speed transmissions?

GM 6 speed transmissions are very advanced and leakage proof systems and if anything is leaking out of them then this could cause transmission overheating. It is definitely a sign of a problem which may cause serious trouble for you in the future.

What are the signs of this problem with the GM 6 speed transmission?

You would get an error such as P0842 or errors in the similar range which are associated with transmission fluid pressure. If these sensors get a low pressure this will indicate there is not enough fluid and a leakage somewhere in the transmission.

How to solve this GM 6 speed  transmission problem?

Detecting where the leak is and closing it, is the most obvious solution to fix this sign before it causes mechanical damage to your car. Usually the gaskets or the seals in the transmission are worn out or broken to cause a fluid leak.

Why is Shaking and shuddering a problem with GM 6 speed  transmissions?

Because shaking and shuddering would mean the GM 6 speed transmission is not functioning smoothly as automatic transmissions are designed for and also they are meant to be a smoother drive than manual. This could cause a very unpleasant driving and passenger experiences

What are the signs of this problem with the GM 6 speed transmission?

Shaking itself can be taken as a sign of this GM 6 speed automatic transmission problem because automatic transmissions are not meant to shake when loaded or accelerated.

How to solve this GM 6 speed  transmission problem?

Visiting your trusted mechanic or service center at the earliest is possibly the only way to fix this issue as the internal mechanical components or dampers might be worn out and it requires experience and expertise to repair this problem.

Why is Transmission Slippage a problem with GM 6 speed transmissions?

GM 6 speed transmission system is not designed to slip and if you are experiencing slippage then it could cause slow response or further damage to the transmission system. So, it is definitely a sign of a problem with the mechanical components of the transmission.

What are the signs of this problem with the GM 6 speed transmission?

You will be able to sense the gear slip while driving and this would be a good sign if there is slipping. Also, an error code will be displayed if you use a diagnostic tool.

How to solve this GM 6 speed transmission problem?

The solenoids of the two gears might be worn out and need to be replaced. Also, there is a chance that these solenoids might also be broken. Rarely, complete mechanical failure occurs with these transmissions.

Why is Burning smell a problem with GM 6 speed transmissions?

If you get a burning odor, your GM 6 speed transmission fluid is probably overheating due to clutch debris, breakdown of metallic components and sludge. So this sign is a cause for concern.

What are the signs of this problem with the GM 6 speed transmission?

The smell itself should be a good sign that there is something wrong with your GM 6 speed transmission. However you will get a more detailed sign if you use a software diagnostic tool.

How to solve this GM 6 speed transmission problem?

Check the transmission oil and its level. If it is too low then fill the required amount of oil in the transmission. If it is too dirty, then drain the entire oil from the transmission and fill it again. Also check for any debris and discarded materials.

How to precisely diagnose these common problems in GM 6 speed transmission?

To properly diagnose these problems, you need a scan tool to read these codes from the Transmission Control Unit. Firstly, If a GM 6 speed transmission is malfunctioning, it immediately informs the driver with an error message on the screen.

How to prevent getting these problems in the first place?

Regularly changing your gearbox oil and other lubricants may save you a lot of trouble and money in the future. Although many experts suggest different number miles for servicing, your car manual will give you a proper recommendation when you should change it.

FAQs: GM 6 speed transmission problems

How much power can a 6L80 transmission handle?

With some modifications, a 6L80E can handle 500 to 600 rear-wheel horsepower in the typical street/strip application, although there are customers who push them all the way to 1,000 hp. They feature custom nitrided steels to prevent warping, and more durable clutch linings that are more resistant to heat. 

How much torque can a stock 6L80E handle?

GM does rate them at 430 lb-ft max input torque and 664 lb-ft max output torque in the trucks, but can handle more. The 6L80E is rated at 800 N-m of Max torque on the input, or 590 ft lbs, up to 6,500 rpm in stock form according to GM tech guide for the crate transmission. 

Conclusion

In this brief guide, we have provided you with common problems with GM 6 speed transmission and what you can do to rectify these problems before they worsen.

If you have any questions or comments please let us know.

Citations:

https://www.gm-trucks.com/forums/topic/220655-6-speed-transmission-issues/