VBFIX-logo-web details-chart-web video-logo-web printlink SERVOFIX-logo-web r_and_r_only maillink sonnax-black Facebook-color Twitter-color LinkedIn-color Youtube-color

Symptoms:

  • 3-4 Clutch burned
  • 1-2 Harsh
  • Code 1870
  • Overheated converter
  • Low TCC apply pressure
  • Low line pressure

Cause:

Excess wear at TCC regulator/isolator valve bore allows TCC apply pressure to exhaust.

Correction:

Recover hydraulic control and renew TCC performance by reconditioning the bore and installing Sonnax TCC regulator and isolator valve kit.

4L60-E, 4L65-E, 4L70-E

TCC Regulator & Isolator Valve Kit
Part No. 77754-04K

Any application, including '98-later EC3 units


You need this if... View Instructions

Severe wear of the TCC regulator valve bore 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 77754-04K restores normal TCC operation by restablishing the hydraulic integrity of this circuit.

  • Sleeve manufactured from highly wear-resistant aluminum
  • Hardcoat anodized aluminum regulator valve combats premature wear
  • Isolator valve lengthened to operate in unworn portions of the bore
  • Annular grooves help center valves in bore to reduce future side-load wear
  • Isolator Valve
  • Spring
  • Regulator Valve
  • Regulator Sleeve

December 22, 2014

The Art of the Silver Bullet

Tory Royce

Topics: Diagnostics And Theory Shop Practices Rebuilding Tips Vacuum Testing Transmission GM Aisin AW 4L60-E Transmission 55-50SN Transmission

Read Now

December 09, 2014

20 Years Later: What’s New with 4L60-E PWM Modifications

Topics: Rebuilding Tips Diagnostics And Theory Torque Converter Transmission GM 280mm LU (4L60-E) “VJCX” Torque Converter 300mm (4L60-E) Torque Converter 4L70-E Transmission 4L60-E Transmission 4L65-E Transmission 258mm LU (4L60-E, 5L40-E) Torque Converter 245mm LU (3T40, 3L30, 200C, 4T60-E, 4L60 & E:S-10 only) Torque Converter 298mm LU (250C, 350C, 200-4R, 4L60 & E) Torque Converter

Read Now

January 21, 2013

GM 4L60-E Vacuum Test Guide

Topics: Vacuum Testing Vacuum Test Guides Transmission GM 4L60-E Transmission

Read Now

November 20, 2014

Torque Converter Journal: 20 Years Later - What’s New with 4L60-E PWM Modifications

Topics: Torque Converter Journals Torque Converter Transmission GM 300mm (4L60-E) Torque Converter

Read Now

September 30, 2005

Anatomy of a Transmission: Oil Flow in the Pump-PR-Converter-Cooler Lube Circuits

Gregg Nader

Topics: Diagnostics And Theory Transmission

Read Now

  • 77754 04k combo
  • 77754 04k

You need this if...

See the Part Selection and Reaming Options Instruction sheet to determine which combined Sonnax parts and tool kits will repair your GM 4L60-E PWM and Non-PWM valve body