All You Need To Know About GM 6L80E/6L90E Transmissions

The GM 6L series transmissions are six-speed automatic gearboxes widely used in various General Motors vehicles. The family includes the 6L45, 6L50, 6L80/6L90 and 6L80E/6L90E. In this article we’ll provide comprehensive information about these transmissions, especially the popular 6L80E and 6L90E variants, addressing common questions and concerns.

How Much Does A GM 6L80E or 6L90E Transmission Cost?

The cost of a GM 6L transmission varies depending on the specific model, whether it’s new, used, or remanufactured, and the warranty offered. Prices can range from $2,500 to $3,500. Powertrain Products stocks a wide range of fully remanufactured 6L80E and 6L90E transmissions that meet or exceed OE specifications.

Can I Replace A GM 6L80E/6L90E Transmission Myself?

Replacing a GM 6L transmission is a complex task that requires specialized tools and expertise. Unless you are an experienced mechanic with prior transmission work, it’s advisable to have a professional handle the replacement.

Incorrect installation can lead to further vehicle damage and safety risks. For those confident in their mechanical skills, ensure you have access to detailed service manuals and follow all safety protocols.

Can I Repair A GM 6L80E or 6L90E Transmission Myself?

Repairing a GM 6L transmission involves diagnosing issues, disassembling components, and possibly replacing intricate parts. Given the transmission’s complexity, DIY repairs are not recommended for individuals without substantial experience repairing transmissions.

Professional transmission specialists have the necessary tools and knowledge to perform repairs accurately. Attempting self-repair without adequate expertise can exacerbate problems and void warranties.

What Are The Flaws Of The 6L80E/6L90E?

The 6L80 transmission, while robust, has reported issues such as:

• Torque Converter Failures: Problems with the torque converter clutch can lead to shuddering during acceleration.
• Pressure Regulator Valve Failures: Faults in the pressure regulator valve can cause slipping between gears.
• Cracked Drums: Cracks in the 1-2-3-4/3-5-R drum can result in slipping in reverse or between 2nd and 3rd gears.

Regular maintenance and addressing issues promptly can mitigate these problems. However, for complete peace of mind, a fully remanufactured unit that has had all known issues rectified is preferable.

How Do I Tell Which GM Transmission I Have?

To identify your GM transmission model:

• Locate the Transmission Tag: GM transmissions typically have an identification tag or stamp. It can be found somewhere on the transmission housing.
• Decode the Tag Number: The tag number is a string of numbers and letters that identifies the specific transmission model. Each manufacturer determines the length and format of the transmission tag number.
• Consult a VIN Decoder: Some VIN decoders can provide transmission information based on your vehicle’s VIN.

Accurate identification ensures compatibility when seeking replacements or repairs.

Where Should I Buy A GM 6L80E or 6L90E Transmission?

Purchasing from a reputable supplier ensures quality and reliability. Powertrain Products offers remanufactured GM 6L80E transmissions with enhancements like billet converters, and we supply a new thermostatic bypass. Our products undergo rigorous testing and come with comprehensive warranties, providing peace of mind.

What Vehicles Are Compatible With The GM 6L80E/6L90E Transmission?

The GM 6L80E and 6L90E transmissions are used in various GM vehicles, including:

Use our VIN decoder and transmission tag identification number to confirm which GM  transmission your vehicle is equipped with.

What Is The Difference Between The 6L80 and 6L90 Transmissions?

The 6L90 was introduced just a year after the debut of the 6L80. The primary differences between the two transmissions are:

• Strength and Durability: The 6L90 has enhanced internal components, making it more robust.
• Size: The 6L90 transmission case is 1-3/8” longer, providing extra room to house two additional pinion gears (six total).

These differences make the 6L90 suitable for heavier-duty applications.

Should I Buy A New, Remanufactured, Or Used Transmission?

• New: Offers a full manufacturer warranty but comes at a higher cost and may not have been updated with the latest fixes to address any reliability issues.
• Remanufactured: PPI transmissions are professionally rebuilt to meet or exceed original specifications, including updated components and a world-class warranty.
• Used: A more affordable option, initially, but comes with higher risk due to unknown wear and limited or no warranty. Premature failure can make this a very pricey mistake.

Remanufactured transmissions provide a balance between cost and reliability, making them a popular choice. But not all remanufactured transmissions are the same, so choose a supplier that stands by the quality of their work with an industry-leading warranty.

What Are The Common Issues With GM 6L80E/6L90E Transmissions?

Common issues include:

• Torque Converter Problems: Shuddering during acceleration due to torque converter clutch issues.
• Valve Body and Solenoid Failures: Leading to harsh or delayed shifts.
• Pressure Regulator Valve Failures: Causing slipping between gears.
• Clutch Pack Wear: Resulting in slipping or harsh shifting.

PPI addresses many of the 6L80/6L90 issues with updates like:

• New Luk Double Disc converter: this is what the OEMs are using and eliminates the typical 6L shudder.
• Heavy Duty Billet cover converter: for the heavier use applications eliminates shudder while proving unrivaled heavy duty performance.
• A stator support shaft with upgraded ring seals: The upgraded ring seals eliminate the leakage issues that are common with the stock units.
• Upgraded Sprag clutches: to increase holding capacity.
• A new thermostatic bypass: to replace a high failure item in the OEM transmission lines.

In almost all cases, the transmission must be reflashed before it is used, and all transmission oil coolers should be replaced to prevent potential oil contamination.

Will A Replacement Transmission Come With A Warranty?

We offer a 3-year standard warranty on all of our engines, transmissions, differentials, and transfer cases. That standard warranty can be upgraded to 5 or 7 years or 1 million miles, whichever comes first.

In many cases our warranties surpass the original manufacturer offering, too. That’s because we remanufacture our transmissions to meet or exceed OE specifications, and we rectify all known faults.

For the ultimate protection, you can add our no-fault Pure Care™ Warranty to your purchase. It adds benefits like rental car coverage and increased labor rate reimbursement. Find out more about our comprehensive warranty options here.

GM Transmission Resources

Interest in finding out more about GM transmissions? Find out everything you need to know here:

GM 6L80E/6L90E Transmissions From Powertrain Products

• Warranty Protection Up To Seven Years, One Million Miles
• High-Quality Rebuilds – We Machine and Use New Parts for Optimum Performance
• Known Issues Rectified For Enhanced Performance

Powertrain Products stocks a full range of transmissions for many makes of vehicles. To ensure you get the right replacement part, use your vehicle’s VIN number or Transmission Tag Number.

We’re also the nation’s leading supplier of engines, differentials, and transfer cases. Call us at 888-842-0023 or contact us online.