The 6L80E transmission has been used in everything from pickup trucks to Corvettes. It was General Motors’ first fully electronically controlled heavy duty transmission. Some of its unique features included direct clutch-to-clutch shifting and an advanced computer controller built into the valve body. This gearbox was designed to handle the torque output of some of GM’s biggest V-8 engines. But unfortunately, a number of design flaws led to many of the most common 6L80E transmission problems. Premature clutch failure is a very common problem on the 6L80E. Other common 6L80E transmission problems include:
What Transmission Do I Have?
Cracks in the 1-2-3-4 piston
Early versions of this transmission are known to develop cracks in the 1234 piston and sometimes in the piston itself. Transmission re-manufacturers like Street Smart Transmission will install an updated 6L80 1234 piston and housing to properly correct the problem.
Cracked drum
Many times, 3-5-R clutch problems and failures can be traced back to a failed drum weld. Many rebuilders will simply weld the cracks, but that generally leads to more issues later on. Transmission re-manufacturers like Street Smart Transmission will install an updated 6L80 clutch drum to properly correct the problem.
4-5-6 clutch hub and intermediate shaft
Due to issues with the original manufacturing process, cracks and other damage can cause a catastrophic failure of the 4-5-6 clutch pump and intermediate shaft. These common 6L80E transmission problems are very serious and can obviously cause a number of serious drivability issues. This is why remanufacturing companies often upgrade these components.
Low sprag failure
When the vehicle starts off in first gear, it may feel as if the transmission has shifted into neutral because the low sprag is failing and the low/reverse clutch is the only thing holding the output carrier stationary during first gear.
Stator support shaft cracking and failed seals
One of the most common 6L80E transmission problems is the failure of the stator support seals, and cracking of the stator support shaft. These issues can cause problems like delayed shifts, harsh shifts and clutch failure. Remanufacturing companies like Street Smart Transmission inspect each stator support shaft for signs of damage, then install upgraded seals to solve the problem.
The 6L80E transmission problems listed above are just some of the issues that owners might face. For a more in-depth look at some of the 6L80E technical service bulletins/TSB, 6L80E diagnostic trouble codes/DTC, as well as other known issues with this transmission, click here.
If you are unsure about all of the technical jargon listed above, just know that most of these 6L80E transmission problems will cause at least one or more of the following symptoms:
- Check engine light
- Harsh, delayed or erratic shifts
- Engine stalls
- Transmission shudders/shakes when coming to a stop or accelerating
- Getting stuck in gear
- Vehicle won’t move when in gear
- Reduced fuel economy
- Transmission overheats
Transmission problems are some of the most expensive repairs on a vehicle. If you haven’t had any luck getting the problems fixed, then these are your three best options:
Buy a Used 6L80 Transmission
If you wanted to save some money, you could go down to the local junkyard and buy a used 6L80 transmission. But keep in mind, it’s coming out of a wrecked or otherwise totaled vehicle. This means you don’t know how it was maintained, if it was abused or what the condition of the internal components really are. So you have no way of knowing if you are going to get 30 miles or 30,000 miles out of it. And that replacement warranty you get from the junkyard isn’t going to cover the labor cost that you’ll have to pay a mechanic to install a replacement transmission if the first used 6L80 breaks.
Buy a Rebuilt 6L80 Transmission
If you don’t want to risk future problems from a used transmission, then you might consider buying a rebuilt 6L80 transmission from a mechanic or transmission shop. In this scenario, they basically take your existing transmission and replace all of the main seals clutches and other “wear parts”. A rebuilt 6L80 transmission is obviously better than a used one. However, most mechanics and repair shops don’t have the experience and equipment to inspect every single component for signs of damage, warping and any other condition that might cause the parts to fall below the original manufacturer’s specifications. Plus that rebuilt transmission warranty may only be honored by a few local transmission shops.
Buy a Remanufactured 6L80 Transmission
Unlike a rebuilt 6L80 transmission, a remanufactured 6L80 transmission has been completely disassembled and then re-engineered on an assembly line. Each component is inspected, cleaned, and reconditioned by a technician that specializes in that particular stage of the process. All of the critical elements including the case, gears, valve body, shafts, pumps, and the torque converter are tested to ensure that they meet original equipment (OE) tolerances and standards. And any part that doesn’t meet the original specifications is either machined until it does or replaced with a brand new part.
Once all of the components meet specification, they’re sent down an assembly line and the transmission is reassembled. The reman 6L80 transmission is then put on a dyno machine which simulates real-world driving through a software program called C.A.R.S. This allows any leaks and imperfections to be discovered and dealt with before the transmission leaves the factory.
Another benefit of a remanufactured transmission are the updates and upgrades it receives. Once a certain vehicle model has been in production for a few years, small issues with the design are discovered and solutions are implemented. It may be more robust friction materials, stronger seals, stiffer springs, or number of other things. These changes are immediately applied to the new models still in production, and Technical Service Bulletins (TSB’s) are sent to dealers so they know how to deal with problems that may arise. Transmission remanufacturing companies like Street Smart Transmission also get these TSB’s, and implement the changes on their assembly line as well.
What Transmission Do I Have?
If you’d like to learn more about getting a remanufactured 6L80 transmission from Street Smart Transmission, click here.
