Allison Transmission Emergency Vehicle Series User Manual

RETARDER
The self-contained retarder is at the output of the transmission and consists of a
vaned rotor which rotates in a vaned cavity. The rotor is splined to and driven by
the output shaft. An external accumulator holds transmission fluid until the
retarder is activated. When the retarder is activated, the fluid in the accumulator is
pressurized by the vehicle air system and directed into the retarder cavity. The
interaction of the fluid with the rotating and stationary vanes causes the retarder
rotor and output shaft to reduce speed, slowing the vehicle or limiting speed on a
downhill grade. Refer to USING THE HYDRAULIC RETARDER for additional
information.
When the retarder is deactivated, the retarder cavity is evacuated and the
accumulator is recharged with fluid.
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Allison Transmission Emergency Vehicle Series Specifications

General

Brand	Allison Transmission
Model	Emergency Vehicle Series
Category	Microphone system
Language	English