Sonnax 2nd Gear "Corvette" ratio servo kit 77701-04K provides increased apply area resulting in improved holding power for firmer 1-2 and 3-4 shifts in 4L60 (700-R4) and 4L60-E transmissions. The servo piston features upgraded Viton^® D-rings in place of the OE seal rings for improved sealing during apply and release.

• Upgrade used for high performance or heavy-duty towing applications
• Improved D-ring sealing configuration
• Compatible with Sonnax 4^th Gear super hold dual servo kit 77767K.