Service Manual

310-2400/2600 IZT
2
INTRODUCTION
The purpose of this manual is to provide
information useful in servicing the Hydro-Gear
Integrated Zero Turn (IZT) transaxle. This man-
ual includes the IZT’s general description, hy-
draulic schematic, technical specifications, ser-
vicing and troubleshooting procedures.
The transaxle normally will not require servicing
during the life of the vehicle in which it is
installed. Should other servicing be required,
the exterior of the transaxle will need to be
thoroughly cleaned before beginning most
procedures.
GENERAL DESCRIPTION
The 310-2400/2600 is a self contained unit de-
signed for the transfer and control of power. It
provides an infinitely variable speed range be-
tween zero and maximum in both forward and
reverse modes of operation.
This transaxle uses a variable displacement
pump with a maximum displacement of 10cc
per revolution, and motor with a fixed displace-
ment of 21cc per revolution. The variable dis-
placement pump features a cradle mounted
swashplate with a direct-proportional displace-
ment control. Reversing the direction of the
swashplate reverses the flow of oil from the
pump and thus reverses the direction of the
motor output rotation.
The pump and motor are of the axial piston de-
sign and utilize spherical nosed pistons which
are held against a thrust race by internal com-
pression springs.
The 310-2400/2600 has a self contained fluid
supply and an internal filter. The 310-2400 fluid
is forced through the filter by a positive “head”
on the fluid in the housing/expansion tank with
an assist by the negative pressure created in
the pump pistons as they operate. The 310-
2600 fluid is drawn through the internal reser-
voir and feeds the fixed displacement gerotor
charge pump. Excess fluid in the charge circuit
is discharged over the charge relief valve and
dumps back to case.
The check valves in the 310-2400/2600 center
section are used to control the makeup flow of
the fluid to the low pressure side of the loop.
A bypass is utilized in the 310-2400/2600 to
permit moving the vehicle for a short distance
at a maximum of 2 m.p.h. (3.2 Km/h) without
starting the engine. The 310-2400/2600 is con-
figured for both floating disc and cog style park-
ing brakes.
SECTION 1. DESCRIPTION AND OPERATION
WARNING
Actuating the bypass will result in the
loss of hydrostatic braking capacity.
The machine must be stationary on a
level surface and in neutral when
actuating the bypass.