Hydro-Gear 310-0750 / 310-0800; General - Simplicity LTH series Service Manual

HYDRO-GEAR 310-0750 & 310-0800

General

The Hydro Gear 0750/0800 uses a 10cc variable dis-
placement pump and a 21cc fixed displacement motor.
The variable pump features a cradle swashplate with
direct-proportional displacement control. Reversing the
tilt of the swashplate reverses the flow of oil to the motor,
which changes the direction of motor rotation.
The pump and motor are of the axial piston design, and
both have spherical nosed pistons which are held
against a thrust race by internal compression springs.
The fluid supply for the hydrostatic transaxle is contained
within the housing and drawn through an integral filter
before entering the pump. Two check valves are used to
direct excess flow to the low pressure side of the loop.
IMPORTANT: Cleanliness is a primary means of
assuring satisfactory life on new or repaired units.
Cleaning parts by using a solvent wash and air dry-
ing is usually adequate. As with any precision equip-
ment, all parts must be kept free of foreign materials
and chemicals.
Figure D–1 Hydro-Gear Model 0750/0800 Hydrostatic Transaxle
7D Hydro-Gear 0750 / 0800
• Protect all exposed sealing surfaces and open cavities
from damage and foreign material.
• Prior to removing and disassembling the transaxle, the
tractor should be steam cleaned or blown with com-
pressed air before beginning any repairs.
• It is recommended that all seals be replaced before
transaxle is reassembled. Lightly lubricate all seals
with a clean petroleum jelly prior to assembly.
• After the transaxle is removed from the tractor, remove
all external components such as the brake arm, brake
actuating pins, control arm, cooling fan, input pulley,
and frame mounting hardware before separating the
case halves.
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7 Transmission Repair