4L60E 4L65E Transmission TCC Regulator & Isolator Valve Kit Sonnax 77754-03K
Fits '97-earlier Non-EC3 units only
GM 4L60-E, 4L65-E and 4L70-E unit, severe wear of the TCC regulator valve bore is caused by oscillation of the OE valve allows regulated converter apply pressure to exhaust. This is a primary cause for TCC-related slip code P1870 and overheated converters. Exhausting apply pressure also diminishes line pressure, which can result in burnt clutches. Excess wear at the isolator valve bore reduces TCC apply pressure.
Reconditioning the bore and installing Sonnax TCC regulator and isolator valve kit 77754-03K restores normal TCC operation by shoring up the hydraulic integrity of this circuit.
10% Higher apply pressure
Isolator valve lengthened to operate in unworn portions of the bore
Sleeve manufactured from highly wear-resistant aluminum
Hardcoat anodized aluminum valves combat premature wear
Annular grooves help center valves in bore to reduce future side-load wear
Contents
Isolator Valve
Spring
Regulator Valve
Regulator Sleeve