4L60-E Transmission Features & Benefit
OVERVIEW
An extremely versatile transmission, the 4L60-E serves in a wide range of applications. Its sophisticated electronic controls and high-torque capabilities allow it to serve in everything from the high-performance Firebird to GMC pickups and SUVs.
NEW OR CHANGED FOR 2001 MODEL YEAR
* Light-Weight Transmission Case for C5 Corvette
* LS1 Opel Omega Application
* 4L60-E HD version
CUSTOMER BENEFITS
TWO-PIECE CASE
The 4L60-E uses a two-piece transmission case with a 360-degree bell housing that completely encloses the torque converter assembly, instead of traditional three-piece construction with a partial bell housing. The result is a dramatic increase in powertrain stiffness and significantly reduced levels of noise and vibration.
This bell housing is modified to suit the wide range of vehicles the 4L60-E serves in, which includes a large line of trucks as well as the Firebird.
ELECTRONIC CONTROLLED CAPACITY CLUTCH (ECCC)
The 4L60-E uses an electronic controlled capacity clutch (used instead of a mechanical lock-up clutch). This clutch uses sophisticated electronics to maintain very small amounts of slip between the pressure plate and the torque converter housing cover. The ability to precisely control continuously variable amounts of slip leads to reduced torque pulses and allows the clutch to be applied at lower vehicle speeds and with smoother engagement. This results in improved drivability and better fuel economy.
ADAPTIVE SHIFT CONTROL
The 4L60-E uses sophisticated electronics to modify shift patterns as conditions dictate. The Powertrain Control Module (PCM) monitors factors such as throttle position, vehicle speed, gear range, temperature and engine load. The PCM also measures changes in the operating condition of the vehicle, which occur naturally over time as components wear. Based on these measurements, shift timing and hydraulic line pressure are adapted to maintain optimum shift feel under different conditions - for example, during heavy hauling or trailering. This results in improved drivability and fuel economy. The PCM also allows the system to self-adjust for minor variations in each new unit, ensuring that every customer experiences consistent performance, and ensuring that the transmission will produce a constant high level of performance for the life of the car.
ABUSE AND SHIFT TORQUE MANAGEMENT
When a driver mistakenly subjects a vehicle to an abusive maneuver, such as moving quickly from drive to reverse while rocking the car to get out of a snow drift, abnormal wear can occur. The 4L60-E's PCM helps to protect the powertrain by retarding spark to reduce engine output during such situations. Similarly, the PCM briefly cuts engine torque prior to each shift to reduce driveline lash, thus producing smoother shifts.
SHIFT STABILIZATION
A common problem in climbing or descending hills is "shift business," which is the tendency of the transmission to hunt between gears. The PCM addresses this issue by sensing when the vehicle is operating on a grade and selecting and holding an appropriate gear, based on throttle position, engine speed and other factors.
SECOND GEAR START
The second gear start option on the 4L60-E provides an extra measure of security and control in hazardous driving conditions. By moving the gear selector to the D2 position, the driver can reduce engine torque to the drive wheels, increasing control during initial acceleration on slippery roads.
LOW MAINTENANCE
The 4L60-E uses long-life DEXRON III transmission fluid, which has a 100,000-mile service interval under normal use (50,000-mile for severe use). Additionally, the PCM monitors operating conditions of the transaxle and alerts the driver with a warning light if there is a deterioration that would cause a significant loss in vehicle performance, such as shift feel or drivability. The PCM also monitors for deteriorations that would allow the vehicle to exceed acceptable emissions levels, in compliance with OBD II regulations.
HISTORY
In 1999 the Hydra-matic 4L60-E received several improvements, including new pump cover seals for improved sealing, new clutch plate materials for improved durability and performance, and Teflon-coated bushings to reduce friction.
LEADERSHIP
"We are very proud of the teamwork and effort that went into the 4L60-E HD program. It was a "go fast" program that required the team to go from project initiation to the start of production in just 13 months. That included not only the redesign of many parts, but also validation of the design and the manufacturing and assembly system. This program is a win-win for both the vehicle and powertrain." --Steve Ford, Total Integration Engineer, 4L60-E.
