Introduction
The purpose
of
this manual is to provide information
useful in servicingtheHydro-GearIntegratedHydro-
static Transaxle (IHT). This manual includes component
description,troubleshooting,maintenanceandrepair
procedures.
A
transaxle normally
will
not require servicing during the
lifeof the vehicleinwhichit
is
installed. Should servicing
be
required, the unit must be removed fromitsinstalled
location and thoroughly cleaned before beginning
most
procedures.
General Description
The Integrated Hydrostatic Transaxleisa
self
contained
unit designed for the transfer and control of power.
It
provides an infinitely variable
speed
range between zero
andmaximum in both forward and reverse modes of
operation.
The IHT uses a variable pump with a maximum displace-
ment of 1Occ per revolution, and a motor with a fixed
displacement of 21cc per revolution. The variable
dis-
placement pump features a cradle swashplate with a
direct-proportional displacement control. Reversing the
direction of tilt of the swashplate reverses the flow ofoil
fromthepumptothemotorandthusreversesthe
direction of the motor output rotation. Thefixeddisplace-
ment motor uses a
fixed
swashplate.Thepumpand
motor are of the axial piston design, and both utilize
spherical nosed pistons which are held against a thrust
race by internal compression springs.
The IHT has a self-contained fluid supply and an integral
filter. The fluid
is
forced through the filter by a positive
"head" on the fluidinthe housing/reservoir with an assist
by the negative pressure createdinthe pump pistons
as
they operate.
Charge check valvesinthe center section are usedto
control the makeup flow of fluid to the low pressure side
of the
loop.
The IHTisfilled and tested at the factory and should
not
require fluid or filter changes unless the fluid becomes
contaminated.
A
cam style, block
lifting
bypass
is
utilizedinthe IHT to
permit moving the vehicle for short distances at a maxi-
mum of 2 mph without starting the engine.
WARNING
!!!
Actuating the bypass
will
resultinthe
loss
of
hydro-
static braking capacity.
The
machine must
be
sta-
tionary and on a level surface andin neutral when
actuating the bypass.
The IHT includes an integral differential which utilizes
heavy duty heat treated bevel gears.
A
"cam" style armisutilizedtoactuate aninline floating
multidisc parking brake. The brake discs are enclosedin
a cavity that
is
sealed from theoilsupply.
IHT
Flow
Illustration
310-0500/0750
IHT
Page
3
