17
HYDROSTATIC TRANSAXLE BELT
TENSION ADJUSTMENT
1. Stop engine and remove key.
2. The hydrostatic transaxle belt tension is
adjusted through a spring loaded idler pulley.
3. The tension can be adjusted by loosening the (2)
hex nuts on the end of the spring support bolt
and turning them until the spring length is 3-
7/16” (Shown at right). Tighten the jam nuts together.
HYDROSTATIC TRANSAXLE (MOTION
DRIVE) BELT REPLACEMENT
1. Stop engine and remove key.
2. Relieve the belt tension on the drive belt (See
Belt Adjustment section) and drop the belt from
the electric clutch deck pulley at the rear of the
unit.
3. Remove the electric clutch anti-rotation bracket
at the rear of the unit.
4. Relieve the spring tension on the motion drive
belt by loosening the (2) hex jam nuts on the end
of the spring support bolt.
5. Remove the old belt.
6. Install the new belt being sure the belt is properly
routed and positioned in all sheave grooves.
7. Adjust tension on the belt by adjusting the length
of the spring on the idler (See Belt Adjustment
section).
8. Reinstall the electric clutch anti-rotation bracket,
the deck belt and re-tension the deck belt (See
Deck Belt Adjustment section).
START-UP MAINTENANCE
Bush Hog recommends the use of SAE 20W50
motor oil in the hydrostatic reservoir.
HYDROSTATIC TRANSAXLE MAINTENANCE
The hydrostatic transaxle units normally do not
require regular fluid changes. The system filter should
HIGH PRESSURE HYDRAULIC FLUID LEAKS
CAN PENETRATE SKIN CAUSING SERIOUS
INJURY AND GANGRENE.
INJECTED FLUID MUST BE SURGICALLY
REMOVED WITHIN A FEW HOURS BY A DOC-
TOR FAMILIAR WITH THIS TYPE OF INJURY.
TO AVOID SERIOUS INJURY FROM
PRESSURE LEAKS:
● USE CARDBOARD AND NOT HANDS TO
SEARCH FOR LEAKS.
● RELIEVE HYDRAULIC PRESSURE BEFORE
WORKING ON SYSTEM.
● CHECK HYDRAULIC HOSES, LINES, AND
CONNECTIONS FOR TIGHTNESS AND
GOOD CONDITION BEFORE APPLYING
SYSTEM PRESSURE.
WARNING
be changed after the first 50 hours of break-in, then
every 200 hours thereafter. The fluid and filter should
be changed and the system cleaned if the fluid
becomes contaminated with foreign matter (water,
dirt, etc.).
FLUID VOLUME AND LEVEL
Certain situations may require additional fluid to be
added or even replaced. Refer to the Figure below
for the proper fill port location. 79 fl. oz. is the correct
amount of fluid to add to an empty transaxle.
The level of fluid in the transaxle may be checked by
removing the plastic breather tube and inserting a
clean, straight metal rod down through the fill port
until it bottoms out. Remove the rod and the oil
should extend approximately 4-1/4” up the rod.
IMPORTANT
Do Not Overfill
If you overfill the transaxle while the unit is
“cold”, it may overflow as it reaches normal
operating temperatures. The oil level should not
be above the manufacturer’s suggestions out-
lined in this manual. This will allow the space
needed for the oil to expand as it warms up.
Recheck the fluid level once the unit has been oper-
ated for approximately one minute.
FLUID CHANGE
In the event of oil contamination or degradation, oil
addition or change may alleviate certain perfor-
mance problems. It is essential that the unit exterior
be free of debris prior to fluid maintenance.
Remove the oil drain plug from the bottom of the unit
to facilitate oil change. When reinstalling oil drain
plug torque the plug to 180 - 240 in. lbs.
HYDROSTATIC BELT DIAGRAM
Clutch Anti-rotation
Bracket
Spring Loaded
Idler
Spring Support Bolt
Adjustment
Spring
Length
3-7/16”
