From Wikipedia...
4L60-E
The TH700R4 was renamed "4L60" (
RPO MD8) following the new General Motors naming convention when the electronic version, 4L60E (RPO M30), was phased in as the 4L60 was being phased out. This happened in 1993 for trucks, vans, and SUVs, and 1994 for rear wheel drive passenger cars. In 1996, a bolt-on
bell housing was phased in (along with a six-bolt tailhousing) for S-10 Trucks and S-10 Blazers and beginning in 1998 for all other applications. Beginning in 1998 a new 300mm torque converter with improved higher-capacity internals, 300mm style input shaft, and 300mm style pump was also introduced on models coupled to a Gen III Small Block. The 4L60E is rated to handle up to 360 ft⋅lb (490 N⋅m) of torque. It weighs 133 pounds without transmission fluid.
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The 4L60E family of transmissions use 2 shift solenoids, initially called Shift Solenoid A & Shift Solenoid B, later changed to comply with OBD II (On Board Diagnostics revision 2) regulations to 1-2 Shift Solenoid & 2-3 Shift solenoid. By activating and deactivating the solenoids in a predetermined pattern by the PCM, 4 distinct gear ratios can be achieved. The last 4L60Es were only used in the GM Vans in 2013, before being replaced by the 6L80E. The shift solenoid pattern, also sometimes referred to as solenoid firing order, is as follows;