- 6L80 vs. 6L90:
- The 6L90 is a heavy-duty version of the 6L80 six-speed automatic, with a strengthened input gearset that has two additional pinion gears (six in total) and a strengthened output gearset that uses wider gears than the 6L80. Its flexibility extends to the clutches, where the 6L90 has one more clutch plate in each clutch than the 6L80 for heavy-duty applications. There is also a 6L90 version without the additional clutch plate to more closely match application requirements, where appropriate.
The 6L90 shares about 75 percent of the parts as the 6L80, although the case of the 6L90 is 35 mm longer than the 6L80 case. The 6L90’s case also accommodates additional fasteners between the transmission and the transfer case for improved driveline noise/vibration performance.