The 6L80 is GM’s six-speed automatic with two overdrive gears and electronic control built into the transmission, used in GM trucks, SUVs and performance cars from 2006 on. The 4L80E is an older, heavier four-speed built for heavy-duty trucks and vans, known for strength and popular in swaps. The 6L80’s wider gear spread gives better launch and lower cruising rpm; the 4L80E’s appeal is its simplicity and toughness under heavy loads.
6L80 vs 4L80E at a glance
| 6L80 | 4L80E | |
|---|---|---|
| Gears | 6 (two overdrives) | 4 (one overdrive) |
| Gear ratios | 4.03 / 2.36 / 1.53 / 1.15 / 0.85 / 0.67 | 2.48 / 1.48 / 1.00 / 0.75 |
| Control | Controller built into the transmission | External control from the engine or transmission computer |
| Typical use | Half-ton trucks, SUVs, Camaro, Corvette | Heavy-duty trucks and vans, swaps |
| Size | Compact for its capacity | Long and heavy |
| Fluid | Dexron VI | Dexron VI |
Gearing and drivability
The 6L80’s deep first gear helps a vehicle launch with a taller axle ratio, and its two overdrives drop highway rpm. The 4L80E’s tall first gear and single overdrive suit heavy-duty trucks with low axle ratios. In a swap, choose the axle ratio together with the transmission; see gear ratio calculator.
Swapping either one
Both need electronic control in a swap. The 4L80E needs a compatible computer or stand-alone controller; the 6L80 needs its built-in controller programmed for the vehicle and engine. See 6L80 swap, 4L60E to 4L80E swap and LS swap transmission options.
Strength and weak points
The 4L80E has a long record behind heavy-duty engines. The 6L80 is capable in its intended vehicles but has known issues such as torque converter shudder and pump wear; see 6L80E problems and 4L80E problems. For the heavier-duty six-speed, see 6L80 vs 6L90.
What a swap involves beyond the transmission
Swapping between these two means more than the transmission itself. The cases differ in length, so the crossmember position and driveshaft length change. The cooler line fittings, shifter linkage or electronic shifter, wiring and controller all need attention, and the speedometer signal may need correcting. Budget for those parts and the labor along with the unit, and plan the axle ratio at the same time; see transmission replacement cost.
Replacement units we list
- RoadReady Chevy 6L80E: $2,699.00
- StreetMonster Chevy 6L80E: $3,399.00
- RoadReady Chevy 4L80E: $2,599.00
- StreetMonster Chevy 4L80E: $3,299.00
Each includes a torque converter; see 6L80E transmissions and 4L80E transmissions.
More guides: 4L80E vs 4L85E · 6R80 vs 6L80 · 6L80 vs 8L90 · how long a 6L80 lasts · how much power a 6L80 can handle · how much power a 4L80E can handle.
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