Issue Summary:
- Beginning with the 2001 model year, all 4L60-E transmissions were produced with a new-design converter-clutch regulator-valve lineup in the valve body.
- 2000-model GM trucks equipped with 4L60-E transmissions and either 4.8- or 5.3-liter engines may experience a driveline vibration at speeds between 35 and 50 mph during conditions of low engine speed and the driver’s foot off the accelerator pedal.
- The valve-body spacer plate for the 4L60-E transmission has changed every year since its introduction in 1993, and the plates will not interchange from year to year. The valve-body casting changed again for model year 2001.
- Some 1999-2001 Chevrolet and GMC C/K trucks and/or Cadillac Escalades with 4.3-, 4.8-, 5.3- or 6.0-liter engines and 4L60-E or 4L80-E transmissions may, on initial startup during cold weather, exhibit late 2-3 and 3-4 shifts and delayed converter-clutch application.
Beginning at the start of production for 2001, all 4L60-E transmissions were produced with a new-design converter-clutch regulator-valve lineup in the valve body, in the location shown in Figure 1.
Reduced bore wear and improved performance for apply and release of the converter clutch.
TCC regulator and isolator valves – This line-up now has re-designed aluminum TCC regulator valve and isolator valves, instead of the previous steel (see Figure 1).
Valve-body casting – Has changed in the worm-track areas that are identified inside the circles (see Figure 2) to accommodate the new-design converter-clutch regulator and isolator valves.
Spacer plate – Two holes in the spacer plate have been revised, as shown in Figure 3, to accommodate the new-design converter-clutch regulator and isolator valves.
None of the parts listed above will interchange with those of the previous design level. However, when new-design valve body and spacer plate are used as a service package, they will service models back to 1998.
2000-model trucks equipped with 4L60-E transmissions and either 4.8- or 5.3-liter engines may experience a driveline vibration at speeds between 35 and 50 mph during conditions of low engine speed and the driver’s foot off the accelerator pedal.
The torque-converter clutch being applied during these low-engine-speed conditions (100-1,400 rpm) transfers engine torsional vibration into the drive-train, resulting in noises and vibration that could be either heard or felt.
Verify the vehicle year. On 2000 models, the 10th digit of the VIN is Y. Next, verify the engine size, using the eighth digit of the VIN. V indicates a 4.8-liter with RPO code LR4. T indicates a 5.3-liter with RPO code LM7. These codes are on the left side of the engine block below the cylinder head. Once you have verified this information, you will need to reprogram the vehicle’s PCM. Refer to the chart in Figure 4 for the appropriate calibration number.
Special Correction:
On any ECC application requiring the torque converter to contain a woven-carbon clutch, be sure that this style clutch is used. Kevlar, cellulose or any material other than the special carbon clutch by General Motors will not live in this environment and also may cause driveline vibration before failure.
The valve-body spacer plate for the THM 4L60-E transmission has changed every year since its introduction in 1993, and the plates will not interchange from year to year. The valve-body casting changed again for model year 2001, and at that time the ID code on the spacer plate went to three digits (see Figure 5). The location of the ID code stamped into the spacer plates also is shown in Figure 5.
Use the chart below that refers you to a figure number to identify the spacer plates, which models they fit and the part number if you need to buy one.
- Refer to Figure 6 for 1993 4L60-E spacer-plate identification.
- Refer to Figure 7 for 1994 4L60-E spacer-plate identification.
- Refer to Figure 8 for 1995 4L60-E spacer-plate identification.
- Refer to Figure 9 for 1996 4L60-E spacer-plate identification.
- Refer to Figure 10 for 1997 4L60-E spacer-plate identification.
- Refer to Figure 11 for 1998 4L60-E spacer-plate identification.
- Refer to Figure 12 for 1999 4L60-E spacer-plate identification.
- Refer to Figure 13 for 2000 4L60-E spacer-plate identification.
- Refer to Figure 14 for 2001 4L60-E spacer-plate identification.
- Refer to Figure 15 for 2002 4L60-E spacer-plate identification.
- Refer to Figure 16 for 2003 4L60-E spacer-plate identification.
Some 1999-2001 Chevrolet and GMC C/K trucks and/or Cadillac Escalades with 4.3-, 4.8-, 5.3- or 6.0-liter engines and equipped with the 4L60-E or 4L80-E transmission may, on initial startup during cold weather, exhibit late 2-3 and 3-4 shifts and delayed converter-clutch application.
When you view solenoid command on the scan tool, the scan tool confirms that the late shift is being commanded and no TCC signal is sent until the vehicle is driven for a few miles, at which time the 2-3 and 3-4 shifts and TCC operation return to normal.
GM has revised cold-weather transmission-shift characteristics on these vehicles to provide faster engine warm-up and improved heater performance.
During the initial startup, if intake air temperature is below 32°F (32°C) the 2-3 and 3-4 shifts and TCC application will be affected as follows, which is considered normal.
2-3 Shift:
- If the throttle is less than 37% open, the 2-3 shift will occur at a minimum speed of 32 mph (51 km/h).
- If throttle opening is more than 37%, the 2-3 shift will revert to a normal pattern.
- When engine-coolant temperature reaches 171°F (77°C), the 3-4 shift will revert to a normal pattern.
TCC Application:
- If the transmission-fluid temperature is less than 62.6°F (17°C), TCC operation will be inhibited and will not resume until transmission-fluid temperature is greater than 68°F (20°C).
- Refer to Chevrolet/GMC factory TSB 01-07-30-013A
December 2003 Issue
Volume 20, No. 12
- THM 4L60-E: New-Design Valve Body and Spacer Plate for 2001
- THM 4L60-E: Driveline Vibration
- THM 4L60-E: 1993-2003 Spacer-Plate Identification
- THM 4L60-E/4L80-E: Late Shifts When Cold