Corvette Servo
A 4L60E Corvette servo is a popular, easy-to-install performance upgrade for GM 700R4/4L60E/4L65E/4L70E transmissions, featuring a larger piston for firmer, faster 1-2 and 2-3 shifts by applying more force to the 2-4 band, improving holding power and shift quality, especially for trucks or performance vehicles, and often combined with shift kits for better results. It works by increasing the servo’s apply area, allowing quicker band release for the 3-4 shift and firmer engagement.
There are multiple options when it comes to buying a corvette servo. You can buy a kit from Sonnax, Transgo, or aftermarket versions manufactured abroad. They all accomplish the same thing. The kit will usually contain the same parts. The cheapest option has you take some parts from your original servo and use with the parts included in the kit. Alternatively, you can just buy the whole servo assembly.
Sonnax Super Hold servo
Sonnax offers a 2nd gear and a separate 4th gear super hold.
Sonnax 2nd gear super hold servo kit 77911-03K for GM 4L60 (700-R4), 4L60-E, 4L65-E and 4L70-E transmissions delivers 18% more apply area than the “Corvette” servo (largest OE). It’s the perfect choice for performance applications when a larger-than-OE servo is desired, and its unique design avoids the timing flaws and excessive shock loads found in other aftermarket servos.
Sonnax 4th Gear super hold dual servo kit 77767K features 40% more apply surface area for greater holding power in GM 4L60 (700-R4), 4L60-E, 4L65-E and 4L70-E units. Vehicles with these transmissions often exhibit poor 3-4 shift quality and experience band failure in performance applications.
Superior Super Billet Servo
Similar to Sonnax, this is made up of a 2nd and 4th gear servo.
This Problem Solver deals with these problems: Sluggish performance when positive shift is demanded; Lack of holding power in 2nd. Voted as One of Transmission Digest’s “10” Best Products for 1997. Largest apply area available for 700-R4. 35 percent more apply area than the Corvette servo. Super positive 1-2 shift. Quicker servo release on the 4-3 downshift. Positive 3-2 kick down. Adjustable pin tip included to set perfect band clearance. Great for heavy service, towing, racing and off-road. Also can be installed on the 4L60-E. Kit contains two-piece 6061-T6 billet aluminum piston set with three piece steel washer set, servo clip, servo pin extender, custom return spring and four piece Teflon sealing, ring and O-ring set.
This billet aluminum Super Servo is the 4th Gear apply piston & outer cover. This upgrade gives you better holding capacity in 4th gear. Firmer 3-4 shifts and more positive 4-3 down shifts. This servo utilizes a lip seal design on the piston for less fluid blow-by or leakage. The servo also provides proper 4-3 band release for no drag.
