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 D-rings in place of the OE seal rings for improved sealing during apply and release. This kit is compatible with Sonnax 4th Gear Super Hold dual servo kit 77767K.

• Upgrade used for high performance or heavy-duty towing applications
• Improved D-ring sealing configuration