March 08, 2023
GM 6L45/50, 6L80/90 No Movement Conditions: Analysis & Repair Tips
Jim Mobley
Mid 2010-earlier GM 6L45/50/80/90 transmissions have a tendency to set a P0751 (shift solenoid 1 malfunction) code. One of the causes of this is the OE spring force at the clutch select valves inhibiting movement of the valves, affecting proper control of clutch apply fluid.
Early-model production has updates made to reduce the spring force. However the updated springs are not available separately from OE, only as part of a new and expensive lower valve body.
Sonnax clutch select valve spring kit 104740-02K updates these springs to the correct lower load to prevent the P0751 code.
Additionally, updates were made to the OE separator plate to further improve clutch feed pressure, clutch backfill exhaust pressure and compensator feed pressure.
If the unit's separator plate is NOT the updated version, Sonnax recommends replacing the plate with the updated version when using this spring kit.
See instructions for details.
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.
March 08, 2023
Jim Mobley
The OE springs at the clutch select valves match the specifications shown below.
OE Clutch Select Valve Spring Specifications | |
---|---|
Outside Diameter | .346" |
Wire Diameter | .032" |
Free Length | .944" |
Total Coils | 8.5 |