Allison Transmission AT 545 Service Manual

2–16 Copyright © 1996 General Motors Corp.
AT 500, 1500 SERIES AUTOMATIC TRANSMISSIONS
j. Reverse Operation (Figure 2–6). Reverse is
the only range in which the forward clutch is not en-
gaged. In this range, the fourth clutch is applied and
this rotates the sun gear shaft assembly (with the front
and center sun gears splined to it) at turbine speed. The
first clutch is applied also, and anchors the rear ring
gear against rotation. The center sun gear rotates the
center carrier pinions, which, in turn, rotate the center
ring gear in an opposite direction. The center carrier is
splined to the planetary connecting drum, which is
splined to the rear carrier. The reverse direction of ro-
tation of the center ring gear rotates the rear sun gear.
This causes the rear planetary pinions to drive the rear
carrier, in a reverse direction, within the stationary
ring gear. This compounding action of the center and
rear planetaries produces a reverse rotation output ra-
tio of 5.02:1.
Figure 2–6. Reverse Power Flow
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V02882
TURBINE SHAFT
SUN GEAR SHAFT
PTO GEAR
FORWARD CLUTCH
THIRD CLUTCH
SECOND CLUTCH
FIRST CLUTCH
FOURTH CLUTCH
✽
TORQUE
CONVERTER
ASSEMBLY
MAIN SHAFT
TORQUE PATH
✽
AT 1500 Series models include a lockup clutch, not active in reverse
CLUTCH APPLIED
OUTPUT
SHAFT

Allison Transmission AT 545 Specifications

General

Brand	Allison Transmission
Model	AT 545
Category	Microphone system
Language	English