Automatic Transmission Overhaul & Testing - 4L60-E: Description
The 4L60-E is a fully automatic transmission consisting of a 3-element hydraulic torque converter with a Torque Converter Clutch (TCC). Two planetary gear sets, 5 multiple-disc clutches, one sprag clutch, one roller clutch and a 2-4 band provide friction elements necessary to produce 4 forward speeds. See Fig 1.
A hydraulic system, pressurized by a variable capacity vane type oil pump, provides pressure required to operate friction elements and automatic controls. The 4L60-E also contains electronic solenoids to control hydraulic operations. A Powertrain Control Module (PCM) receives signals from Vehicle Speed Sensor (VSS), Throttle Position (TP) Sensor, fluid pressure switch assembly, and temperature sensor. These signals help PCM determine when to switch 2 shift solenoids, 3-2 downshift solenoid, and/or TCC solenoid on or off. PCM can also control line pressure via pressure control solenoid (force motor).