Vehicles with GM 4L60, 4L60-E, 4L65-E and 4L70-E transmissions often exhibit poor 3-4 shift quality and experience band failure in performance applications. The Sonnax 4th gear super hold dual servo assembly 77767K features 40% more apply surface area for greater holding power.

• 40% More surface area for greater holding power
• Can be used with OE, Corvette or Sonnax performance 2nd gear servo assemblies
• Easy to install - transmission removal is not required
• D-ring seals for improved sealing
• Billet aluminum cover

The Sonnax 2nd gear super hold servo kit 77911-03K for GM 4L60/4L60-E/4L65-E has 17% more apply area than the “Corvette” servo (largest OE) and maximizes holding power in 2nd gear with more positive 1-2 and 2-3 shifts. Dual seals on the 2nd gear piston and separator ensure positive band apply/release and eliminate cross leaks, which contribute to 2-4 band and 3-4 clutch failure. This servo is the perfect option when more holding power is desired without causing excessively harsh upshifts and downshifts. The included apply pin is longer than the longest OE pin, and has added seals to reduce leakage of 3rd and 4th gear oil pressure. For the ultimate servo combination in your 4L60/4L60-E, Sonnax recommends using the Sonnax 4th gear super hold servo 77767K with the Sonnax 2nd gear super hold servo kit 77911-03K.

• 17% more apply area than OE Corvette servo
• Dual seals on 2nd apply piston and separator
• Servo piston and separator are made from 6061-T6 aluminum
• O-ring seal between pin and 2nd gear piston
• Two PTFE rings seal pin to bore
• Servo pin is made from chromoly steel
• Kit includes all necessary seals