Home/GMC/Sierra 1500/GMC Sierra 1500 (2000-2012)/Repair manual/Automatic Transmission - 4L80-E/4L85-E - Overhaul/Overdrive Range, 4-3 Downshift

Contents

Wiring diagrams Section: Automatic Transmission - 4L80-E/4L85-E - Overhaul

Low and Reverse Band Servo Piston Pin Check

Front End Play Check

Rear Unit End Play Check

Tools Required

Output Carrier Pinion End Play Measurement

Reaction Carrier Pinion End Play

Intermediate Clutch Piston Travel Check

Direct Clutch Piston Travel Check

Forward Clutch Piston Travel Check

Fourth Clutch Piston Travel Check

Overrun Clutch Piston Travel Check

Overdrive Carrier Pinion End Play Check

Transmission Oil Pump Body Flatness Check

Low and Reverse Band Servo Apply Piston Pin Check

Park or Neutral - Engine Running

Reverse

Overdrive Range, First Gear

Overdrive Range, Second Gear

Overdrive Range, 4-3 Downshift

Overdrive Range, 3-2 Downshift

Manual Third Gear

Manual Second Gear

Manual First Gear

All sections

Overdrive Range, 4-3 Downshift GMC Sierra 1500

Automatic Transmission - 4L80-E/4L85-E - Overhaul 1 illustration

Overdrive Range, 4-3 Downshift

In order to obtain the 4-3 downshift, the PCM receives an input signal from the TP Sensor at increased throttle openings. This causes the PCM to de-energize the 1-2 Shift Solenoid (SS) Valve.

Scheme 744

Scheme 744: Overdrive Range, 4-3 Downshift

Scheme 744: Overdrive Range, 4-3 Downshift