The 6R80 and 6L80 are six-speed rear-wheel-drive automatics from different makers: the 6R80 is Ford’s, used in F-150s, Expeditions, Mustangs and other Fords from about 2009, and the 6L80 is GM’s, used in Silverados, Tahoes, Camaros and Corvettes from 2006. Their gear ratios are close, but they are not interchangeable: bellhousing patterns, electronics and controls are specific to each maker. The useful comparison is how each behaves in its own trucks and what goes wrong with it.
6R80 vs 6L80 at a glance
| Ford 6R80 | GM 6L80 | |
|---|---|---|
| Gear ratios | 4.17 / 2.34 / 1.52 / 1.14 / 0.87 / 0.69 | 4.03 / 2.36 / 1.53 / 1.15 / 0.85 / 0.67 |
| Typical vehicles | F-150, Expedition, Mustang, Ranger (later years) | Silverado, Sierra, Tahoe, Camaro, Corvette |
| Control | Electronic, with a controller in the valve body on many applications | Electronic, with a controller built into the transmission |
| Fluid | Mercon LV | Dexron VI |
How they compare on the road
Both have a deep first gear and two overdrive ratios, so launch feel and cruising rpm are similar for a given axle ratio and tire size. Differences owners notice usually come down to calibration in the specific vehicle rather than the hardware. Tire size and axle ratio changes affect both the same way, so recalibrate the speedometer and shift points after changing either.
Known problems
- 6R80: harsh or erratic shifts often tied to adaptive learning, wiring or solenoid faults, and converter shudder; see 6R80 problems.
- 6L80: torque converter shudder, pump wear and valve body issues; see 6L80E problems.
On both, fluid condition and the correct fluid matter; see the transmission fluid chart.
Checking the fluid on either
Many vehicles with either transmission have no dipstick. The level is checked at a check plug or fill port with the fluid at a specified temperature, often with a scan tool reading the fluid temperature. Overfilling and underfilling both cause shift problems, so follow the procedure for your vehicle; see how to check transmission fluid.
Successors
Ford replaced the 6R80 in many trucks with the 10R80, and GM moved many trucks to the 8L90 and 10L80. See 6R80 vs 10R80, 10R80 vs 10L80 and 6L80 vs 6L90.
Which do you have?
Check the build data or transmission tag; model year and engine usually settle it. See what transmission do I have?
Replacement units we list
The RoadReady Ford 6R80 is $3,099.00 and the RoadReady Chevy 6L80E is $2,699.00, each with a torque converter. Browse 6R80 transmissions and 6L80E transmissions.
More guides: 6L80 vs 4L80E · 6R80 vs 6R140 · how much power a 6L80 can handle.
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