• Lube failures
  • Planetary failure
  • Loss of lubrication oil to planetaries
  • Burnt parts & planetaries
  • Gear train noise


The output planetary lube dam traps contamination, blocking lube flow and resulting in comebacks. Inadequate lube flow to the small gears allows them to burn.


Install upgraded Sonnax output planet saver kit to repair and prevent common concerns.


Output Planet Saver Kit
Part No. 104584-90K

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The output planetary assembly in GM 6L90 transmissions has a lube dam, or cover, that directs lube oil flow to the planetary lube feed passages. Over time, the lube dam allows gunk and sludge buildup, which chokes off lubrication. This commonly happens after overhaul, resulting in comebacks due to failed planetary assemblies.

In addition, the large OE pinion pins do not supply lube to the small gears, resulting in burnt gears, pins, bearings, needles and washers. Save the planetary assembly by installing Sonnax output planet saver kit 104584-90K, which includes upgraded pinion pins to supply continuous, critical lube to the small gears.

For GM 6L80 planet saver kit, use 104584-80K.

  • Batwing Thrust Washers (6) Mirrored
  • Batwing Thrust Washers (6)
  • Output Planetary Lube Dam
  • Thrust Washers (12) Large
  • Thrust Washers (6) Small
  • Needle Spacers (3) Large
  • Needle Spacers (3) Small
  • Pinion Pins (3) Large, Lube Upgrade
  • Pinion Pins (3) Small
  • Roller Bearing
  • Roller Needles (234) Short
  • Roller Needles (69) Long
  • Thrust Bearings (3) Various Sizes
  • 6L90 Output Planet Saver Kit 104584-90K