77720HD

High RPM (3-4/FWD) Clutch Spring Kit
Fits 1982-15 700R4, 4L60, 4L60E, 4L65E, 4L65E

This 77720HD  clutch spring kit fits 1982 to 2015 General Motors vehicles equipped with the 700R4/4L60, 4L60E, 4L65E and 4L70E automatic transmission. High-revving engines often have complaints of burnt 3-4 clutch plates with no visible signs of why the clutches failed.

At high RPM, the check ball in the input drum will not seat due to outward centrifugal force creating a leak in the 3-4 clutch circuit. Additionally, minor cross leaks can lead to fluid buildup behind the 3-4 apply piston and become trapped. Without a sufficient air bleed, this trapped oil behind the 3-4 piston can allow the 3-4 clutch to partially apply in 1st and 2nd gear resulting in 3-4 clutch failure at high RPM’s.

Starting in 1988 through the last year of production of the 4L60E series transmission, GM installed load release springs in the input drum help counteract the accidental oil intrusion into the 3-4 clutch circuit. The GM load release springs are a step in the right direction however they have their limitations.  Many techs prefer to install additional frictions in the 3-4 clutch. Depending on the clutch stack up the OE load release springs could be rendered non-functional. Secondly the tension that OE springs provided was inadequate.

Features and benefits:

This TransGo clutch spring kit includes a new 3-4 orifice capsule to mitigate the checkball leak and also provides an additional exhaust for the trapped residual oil. The springs in this kit provide the tension needed to keep the clutches from applying in 1^st or 2^nd at high RPM as well as providing for a cleaner forced throttle 3-2 downshift by helping the 3-4 clutch release faster.

Corrects/Prevents/Reduces:

• 3-4 burnt clutch plates
• Prevents high RPM centrifugal clutch apply
• For use with original or additional clutches
• Faster release of the 3-4 clutch

Includes:

• 3-4 clutch orifice plug
• 3-4 clutch return springs
• Forward clutch return springs
• Installation washer