James B.

iTrader: (1)

The 2.75:1 planetary sets were never offered in any variety of factory 4L80-E that I know of. The 4L80-E HD transmissions used in RV's, busses, Isuzu diesel trucks, etc, have straight-cut gears in the two rear planetaries. The stright-cut gear whine but put less stress on the thrust washers and torrington bearings than helical-cut gear sets do. The HD version also has a few different options for the tailshaft housing including one with a driveline parking brake. The 2.75:1 gear sets are aftermarket parts.