No Overrun Braking - Manual 3-2-1. GMC Truck Envoy

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2006 🢒 Envoy - 4WD 🢒 Transmission/Transaxle 🢒 Automatic Transmission - 4L60-E/4L65-E/4L70-E 🢒 No Overrun Braking - Manual 3-2-1

Checks

Causes

External Linkage

Not adjusted properly

Valve Body Assembly (60)

•	4-3 Sequence valve stuck

•	Checkball mispositioned

•	Spacer plate and gaskets incorrect, damaged or mispositioned

Overrun and Forward Clutch Assembly (644-651)

•	Turbine shaft oil passages plugged or not drilled

•	Turbine shaft seal rings damaged

•	Turbine shaft sealing balls loose or missing

•	Porosity in forward or overrun clutch piston

•	Overrun piston seals cut or damaged

•	Overrun piston checkball not sealing