TRANSMISSION
TRUCK SERVICE MANUAL
Para 1-1/1-4
Section 1. GENERAL INFORMATION
1-1.
SCOPE OF MANUAL
b. Parts Catalog. All replacement parts
should be ordered from your dealer. These parts are
a. Coverage.
This Service Manual
listed in the current HT 700 Series Parts Catalog (SA
describes the operation, maintenance, and overhaul
1268). Do not order by illustration item numb e r s
procedures for the
HT 750CRD
used on exploded views in this manual.
automatic transmission (fig. 1-3 AND 1-4 -). The
1-4. GENERAL DESCRIPTION
major components of the transmission are discussed,
and the function and operation of the hydraulic
a. Automatic Shifting. Automatic shifting is
system and torque paths are explained. Detailed
accomplished in all ranges.
THE DESIGN
instructions are provided for disassembly, rebuild and
assembly. Wear limits information, par t s inspection
INCORPORATES FIVE SPEEDS FORWARD AND
procedures, and torque specifications are also
ONE
REVERSE.THE
TRANSMISSION
WAS
included.
DESIGNED FOR OPERATION WITH A DIESEL
ENGINE.
b. Illustrations. The text is illustrated with
photographs, line drawings, and cross-section views.
b. Torque Converter. A simple, 3element
The overhaul procedures are illustrated mainly by
torque converter (fig 1-4) transmits power from the
photographs. Line drawings are used to supplement
engine to the transmission gearing. The torque
detailed assembly procedures; cross-section views
converter serves as both a fluid coupling and a
illustrate the torque paths and relationship of
torque multiplier.
assembled parts. Cross-section views, color-coded
schematics of the hydraulic system, and all exploded
THE TORQUE CONVERTETER USED IN THIS
views are presented on foldout pages at the back of
TRANSMISSION HAS A STALL RATIO OF 2.8:1.
the manual.
c. Lockup
Clutch.
This
clutch
1-2.
SUPPLEMENTARY INFORMATION
automatically locks the turbine element of the torque
converter to the flywheel. When the vehicle attains
Supplementary information will be issued, as
sufficient speed, hydraulic pressure automatically app
required, to cover any improvements which may
lie s the lockup clutch. When the lockup clutch is
occur after publication of this manual. Check with
applied, the engine output is directed to the
your dealer to insure you have the latest information.
transmission gearing at a 1:1 speed ratio.
A
decrease in speed automatically releases the lockup
1-3.
ORDERING PARTS
clutch.
a. Transmission
Nameplate.
The
nameplate (fig. 1-7) is located on the right-rear side
of the transmission. The nameplate displays the
transmission serial number, part number (assembly
number), and model number. All three of these must
be supplied when o r d e r in g replacement parts or
requesting
service
information.
672
