Is the 6L80E a good transmission? The answer to this question is largely depends on how it has been driven and maintained. This was the first fully electronically controlled transmission from General Motors, and it has a number of unique features that are prone to early failure. In order to avoid this, it is important to ensure that all of the recalls and TSBs/Technical Service Bulletins have been addressed. Otherwise, you could get saddled with a number of expensive transmission problems.
What Transmission Do I Have?
6L80E Transmission Overview
The 6L80E is a 6 speed automatic transmission that uses direct clutch-to-clutch shifting to change gears. This means there are no transmission bands, and the gear selection is controlled by a 32-bit computer controller inside of the valve body 6L80 TEHCM. The driver can manually select gears via the gear selector. Or they can leave it in Drive to take advantage of the increase in fuel economy provided by the two overdrive gears (there is no direct drive).
6 = 6-speed
L = Longitudinal (i.e. RWD/4WD)
80 = 8,000 lb max GVW
E = Electronically Controlled
Common 6L80 transmission problems
- Reverse Fails to Engage If you’ve selected Reverse and your vehicle still won’t move, then it’s possible the park prawl (the metal piece that stops your vehicle from rolling), or one of the clutches has become damaged.
- Slipping Between Gears If you experience slipping in reverse, or between 2-3, then it’s very likely that the 1-2-3-3/5-R drum has developed a crack, which will require an entirely new drum and bearing.
- Slipping in First Gear If you have difficulty getting your vehicle to move from a dead stop, then it’s possible that one of the solenoids is stuck in the ‘off’ position, or there’s a problem inside of the valve body.
Your options on replacing a 6L80 transmission:
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.
