If you own a vehicle with a 6L90 transmission, you may have experienced some of the common problems that plague this unit.
The 6L90 is a six-speed automatic transmission designed by General Motors for longitudinal engines and rear-wheel drive vehicles.
It is known for its performance and fuel economy, but it also has some drawbacks that can affect its reliability and durability.
Some of the 6L90 transmission problems include slipping or no reverse, hard shifts, fluid overheating, torque converter issues, and clutch pack failures.
These problems can cause damage to your transmission and reduce its lifespan.
Fortunately, there are ways to fix them and prevent them from happening again.
In this article, we will show you how to tame the trouble and solve the 6L90 transmission problems with some simple tips and tricks.
You will learn how to identify the symptoms, diagnose the causes, and apply the solutions for each problem.
By following our guide, you will be able to restore your transmission to its optimal condition and enjoy a smooth and comfortable ride.
What Are Some of The Common 6L90 Transmission Problems?
Some of the common 6L90 transmission problems are:
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Slip in reverse or no reverse
This problem occurs when the transmission fails to engage the reverse gear or slips when reversing. The possible causes are low fluid level, worn or damaged clutches, solenoid or valve body issues, or a faulty torque converter.
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Hard shifts to 3rd or 5th
This problem manifests as harsh or delayed shifts from 2nd to 3rd or from 4th to 5th gear. The possible causes are low fluid pressure, faulty solenoids, valve body wear, or clutch pack failure.
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Slip in 3rd or 5th gear
This problem occurs when the transmission slips or flares during acceleration or deceleration in 3rd or 5th gear. The possible causes are low fluid pressure, worn or damaged clutches, solenoid or valve body issues, or a faulty torque converter.
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Transmission Fluid Over Temperature
This problem occurs when the transmission fluid temperature exceeds the normal operating range, which can lead to overheating and damage. The possible causes are low fluid level, restricted fluid flow, faulty cooling system, excessive load, or driving conditions.
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Torque converter engagement/disengagement problems
This problem occurs when the torque converter fails to lock or unlock properly, resulting in reduced fuel efficiency, performance, or drivability. The possible causes are low fluid pressure, faulty solenoids, valve body wear, or torque converter failure.
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Clutch pack failures
This problem occurs when the clutches inside the transmission wear out or break, resulting in loss of power, slipping, or no movement. The possible causes are low fluid pressure, fluid contamination, excessive heat, or abuse.
How Do You Identify The Symptoms Of 6L90 Transmission Problems?
The symptoms of 6L90 transmission problems can vary depending on the type and severity of the problem. However, some of the common signs that indicate something is wrong with your transmission are:
Slip in reverse or no reverse
You may notice that your vehicle does not move or moves very slowly when you shift to reverse. You may also hear a grinding or whining noise from the transmission.
Hard shifts to 3rd or 5th
You may experience a sudden or delayed jerk when your transmission shifts from 2nd to 3rd or from 4th to 5th gear. You may also feel a loss of power or acceleration during the shift.
Slip in 3rd or 5th gear
You may notice that your engine revs up or down without changing the vehicle speed when you are driving in 3rd or 5th gear. You may also see the check engine light or the transmission temperature warning light on your dashboard.
Transmission Fluid Over Temperature
You may see a message on your instrument panel that says “Transmission Fluid Over Temperature” or “Transmission Hot”. This means that your transmission fluid is overheating and can cause damage to your transmission components.
Torque converter engagement/disengagement problems
You may feel a shudder or vibration when your torque converter locks or unlocks. You may also notice a decrease in fuel efficiency or performance when your torque converter is not working properly.
Clutch pack failures
You may experience a complete loss of power or movement when your transmission clutches fail. You may also hear a loud bang or clunk from the transmission when this happens.
How Do You Fix 6L90 Transmission Problems?
There are different ways to fix 6L90 transmission problems depending on the type and cause of the problem. Here are some general steps that you can follow:
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Check the transmission fluid level and condition
Low or dirty fluid can cause many problems such as slipping, overheating, or hard shifting. You should use the recommended DEXRON VI fluid and change it regularly according to the manufacturer’s guidelines.
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Scan the transmission for trouble codes using a diagnostic tool
This can help you identify the specific problem and the possible faulty components. Some common codes related to 6L90 transmission problems are P0700, P0741, P0756, P0776, P0796, and P2714.
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Inspect the transmission components for wear, damage, or contamination
Some of the components that may need to be replaced or repaired are the clutches, solenoids, valve body, pump, torque converter, and reverse drum.
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Perform a transmission relearn procedure after fixing the problem
This can help the transmission adapt to the new parts and settings and improve its performance and shifting. You can do this by driving the vehicle in different modes and speeds for a certain period.
How much does it cost to fix a 6L90 transmission?
The cost to fix a 6L90 transmission depends on the type and extent of the problem, the parts and labor required, and the location and reputation of the repair shop. The average cost to rebuild a 6L90 transmission ranges from $1,500 to $2,500.
However, this may not include the cost of diagnosis, fluid, filter, or other additional services. The cost to replace a 6L90 transmission with a new or remanufactured one may be higher, depending on the availability and quality of the unit.
The cost of a remanufactured 6L90 transmission is around $2,500 to $4,000, excluding shipping and installation fees. The cost of a new 6L90 transmission may vary depending on the dealer and the warranty offered.
What is the lifespan of a 6L90 transmission?
The lifespan of a 6L90 transmission depends on several factors, such as the driving conditions, maintenance, and quality of the parts. The average lifespan for a GM transmission is around 120,000 miles.
However, some transmissions may last longer or shorter than this average, depending on how well they are taken care of and if they encounter any major problems. A Silverado with a V8 engine and a 6L90 transmission may last up to 200,000 miles if properly maintained.
Related Post: Boosting Performance & Reliability: A Guide To 6L90 Transmission Upgrades!
What Are The Symptoms Of A Bad Torque Converter In A 6l90
The torque converter is a device that transfers the engine’s torque to the transmission. It consists of a pump, a turbine, and a clutch that locks and unlocks the converter depending on the driving conditions. A bad torque converter can cause various problems with the transmission and the performance of the vehicle. Some of the symptoms of a bad torque converter in a 6L90 are:
Transmission slipping
This is when the transmission fails to engage the gear or slips out of gear while driving. You may notice that the engine revs up but the vehicle does not accelerate or decelerate. This can be caused by low fluid pressure, worn or damaged clutches, solenoid or valve body issues, or a faulty torque converter.
Rough idling
This is when the engine runs unevenly or erratically at idle. You may feel vibrations or shudders from the engine or the transmission. This can be caused by abnormal pressures or fluctuations in the torque converter.
Rough acceleration
This is when the vehicle jerks or hesitates when accelerating. You may feel a loss of power or a delay in the response. This can be caused by abnormal pressures or fluctuations in the torque converter.
The car won’t move in drive or reverse
This is when the vehicle does not move at all when you shift to drive or reverse. You may hear a grinding or whining noise from the transmission. This can be caused by a completely failed torque converter that prevents the transmission from engaging the gear.
Transmission overheating
This is when the transmission fluid temperature exceeds the normal operating range, which can damage the transmission components. You may see a warning light or message on your dashboard indicating that the transmission is overheating. This can be caused by excessive slipping or friction in the torque converter that generates heat.
Torque converter engagement/disengagement problems
This is when the torque converter clutch fails to lock or unlock properly, resulting in reduced fuel efficiency, performance, or drivability. You may feel a shudder or vibration when the torque converter locks or unlocks. You may also notice a decrease in fuel efficiency or performance when the torque converter is not working properly.
What Cars Came With 6l90?
Some of the vehicles that came with the 6L90 transmission are:
- Cadillac CTS-V Sedan, Coupe, and Wagon (2009-2015) with a 6.2L V8 LSA supercharged engine
- Chevrolet Camaro ZL1 (2012-2015) with a 6.2L V8 LSA supercharged engine
- Chevrolet Express (2007-2021) with various engine options, such as 4.8L V8, 6.0L V8, 6.6L V8 Duramax, and 6.0L V8 CNG
- Chevrolet Silverado HD (2007-2021) with various engine options, such as 6.0L V8, 6.6L V8 Duramax, and 6.0L V8 CNG
- Chevrolet Suburban (2007-2014) with a 6.0L V8 engine
- Chevrolet Corvette (2008-2013) with a 6.2L V8 LS3 engine
- GMC Savana (2007-2021) with various engine options, such as 4.8L V8, 6.0L V8, 6.6L V8 Duramax, and 6.0L V8 CNG
- GMC Sierra HD (2007-2021) with various engine options, such as 6.0L V8, 6.6L V8 Duramax, and 6.0L V8 CNG
- GMC Yukon XL (2007-2014) with a 6.0L V8 engine
- Cadillac Escalade (2007-2014) with a 6.2L V8 engine
6l90 Transmission Filter
A 6L90 transmission filter is a device that filters the transmission fluid and prevents dirt, debris, and metal shavings from entering the transmission components. The transmission filter is located inside the transmission pan and is attached to the valve body.
The transmission filter should be replaced regularly according to the manufacturer’s guidelines, usually every 30,000 to 60,000 miles, to ensure the proper functioning and longevity of the transmission.
There are different types and brands of transmission filters for the 6L90 transmission, such as the Filtertek OE filter, the Summit Racing filter kit, the Genuine GM Parts filter, and others. The transmission filter may vary in shape, size, material, and quality, depending on the manufacturer and the model of the vehicle. The transmission filter should match the specifications and requirements of the 6L90 transmission and the vehicle it is installed in.
To replace the transmission filter, you will need to drain the transmission fluid, remove the transmission pan, disconnect the old filter from the valve body, install the new filter and seal, reinstall the transmission pan, and refill the transmission fluid. You may also need to replace the transmission gasket and the transmission fluid filter magnet.
6l90 Transmission Reset
A 6L90 transmission reset is a procedure that can help the transmission adapt to the new parts and settings and improve its performance and shifting. It can also clear any trouble codes or errors that may cause the transmission to malfunction. A 6L90 transmission reset can be done using a diagnostic tool or by following some simple steps.
To perform a 6L90 transmission reset using a diagnostic tool, you will need to connect the tool to the vehicle’s OBD-II port and follow the instructions on the screen. You will need to select the transmission control module (TCM) and choose the option to reset the transmission adapts.
This will erase the learned values and patterns of the transmission and allow it to relearn them based on the current conditions. You may also need to clear any trouble codes or errors that may be stored in the TCM.
To perform a 6L90 transmission reset without a diagnostic tool, you will need to follow these steps:
- Start the engine and let it idle for a few minutes.
- Shift the transmission to drive and accelerate slowly to 2500 rpm.
- Once you reach 2500 rpm, slow back down to 1000 rpm and repeat the slow acceleration up to 2500 rpm.
- Do this for at least 15 minutes or until the transmission temperature reaches 80°C (176°F).
- Shift the transmission to neutral and let it idle for a few minutes.
- Shift the transmission to reverse and accelerate slowly to 2500 rpm.
- Once you reach 2500 rpm, slow back down to 1000 rpm and repeat the slow acceleration up to 2500 rpm.
- Do this for at least 15 minutes or until the transmission temperature reaches 80°C (176°F).
- Shift the transmission to neutral and let it idle for a few minutes.
- Turn off the engine and remove the key from the ignition.
- Open and close the driver door and wait for 15 to 20 minutes.
- Restart the engine and drive the vehicle normally.
These steps will reset the transmission adapts and allow the transmission to relearn the optimal shift points and pressures based on the current conditions. You may notice some improvement in the transmission performance and shift after the reset.
Conclusion
The 6L90 transmission is a powerful and efficient unit that can handle a variety of vehicles and engines.
However, like any other transmission, it can also suffer from some common problems that can affect its performance and reliability.
Some of the 6L90 transmission problems include slip in reverse or no reverse, hard shifts to 3rd or 5th, slip in 3rd or 5th gear, transmission fluid over temperature, torque converter engagement/disengagement problems, and clutch pack failures.
These problems can cause damage to your transmission and reduce its lifespan.
Fortunately, there are ways to fix them and prevent them from happening again.
In this article, we have shown you how to tame the trouble and solve the 6L90 transmission problems with some simple tips and tricks.
You have learned how to identify the symptoms, diagnose the causes, and apply the solutions for each problem.
By following our guide, you can restore your transmission to its optimal condition and enjoy a smooth and comfortable ride.
We hope you have found this article helpful and informative.
If you have any questions or comments, please feel free to contact us.
Thank you for reading and have a great day!
