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6 speed allison transmission

The older automatic transmission dating from 1989 to 2002 when the 47 RH then the 48-RE transmissions were introduced were designed after the 727 Torqueflight Chrysler transmission and were never suited for the diesel market. The 47- RH and the 48-RE continued to use very old technology that has been passed on for many years. Utilizing bands, hydraulic throttle valves and governor pressure to control shift timing, the 48-RE transmission will never be a smooth shifting transmission or have the consistency of the newer designed transmissions. The first three gears of the 48-RE are spaced evenly while the 4th gear is a massive jump into overdrive. The big jump into overdrive creates a large RPM drop into 4th gear making it somewhat unpleasant for towing.