April 06, 2022
Diagnosing the Infamous GM 8L45, 8L90 3-4 Neutral: Check Your Solenoid Wiring Harness Assembly
Jim Mobley
Later design valve bodies have updated the S4 valve to a single .531" diameter size. Sonnax clutch control valve included in this kit cannot be used in this location or shift complaints will occur.
Sonnax shift Zip Kit 8L45-8L90-SHIFT-ZIP targets the root cause of mulitple shift-related complaints by sealing the critical circuit pressure losses in the GM 8L45 and 8L90 valve body. The kit contains uniquely designed parts to prevent the loss of pressures within the signal accumulator, clutch control and 1-3-5-6-7 accumulator piston circuits. These solutions target wear that results in multiple shift quality complaints and burnt clutches. No special tools are required for installing these parts.
The Zip Kit quick guide provides clear and easy instructions on one sheet to get the unit sealed up and back on the road fast. In addition to general rebuilding tips and technical information, the techncial booklet included in this kit contains vacuum testing information and locations at other key areas of the valve body.
Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.
April 06, 2022
Jim Mobley
August 02, 2022
December 12, 2022
Jim Mobley
May 15, 2023
Maura Stafford
July 27, 2023
Caleb Perham
August 10, 2023
Jim Mobley
It's easy to restore and extend vehicle shift quality with Zip Kits. Uniquely designed, drop-in Sonnax parts target the root cause of valve body complaints and stop critical circuit pressure losses in the most common problem areas of the transmission.