Gravely Hydro Pro Series - Page 20

GB-20
988120, 124, 125, 127
NOTE: Setting the unit to the faster speed range will make
the steering controls more sensitive.
To adjust (Figure 18):
1. Stop engine.
2. Disconnect clevis from speed control arm.
3. Remove speed control arm from hydraulic pump.
NOTE: Save speed control arm and hardware to return unit
to slower speed range.
4. Connect clevis to return to neutral bracket on the
hydraulic pump with clevis pin and hairpin.
5. Repeat steps 1 - 4 for the other pump.
6. Check and adjust tracking as needed.
REMOVE SINGLE LEVER PLATES (988105,
108, 123, 126)
Without the single lever plate, the speed control levers can
work separately to adjust tracking on uneven terrain.
To remove:
1. Remove knobs from speed control levers.
2. Remove and keep single lever plate.
3. Remove and keep nuts.
4. Apply Loc-Tite 495 (or equivalent) to knob threads.
5. Replace knobs on speed control levers.
REPLACING HYDRO PUMP BELT
1. Place speed control levers in neutral position (988105,
108, 123, 126).
2. Remove mower belt from mower clutch sheave
(Figure 19).
3. Remove pump belt idler spring from eye bolt.
4. Remove belt from engine sheave and pump pulleys.
5. Install new belt on engine sheave and pumps.
6. Reconnect idler spring to idler.
7. Put mower belt back on mower clutch sheave.
Faster Speed
Slower Speed
Figure 17
1. Clevis
2. Speed Control
Plate
3. Pump Actuating
Spring
4. Pump Actuating
Spring Anchor
1
2
3
4
1
2
3
4
OG1340
3
3
WARNING: An extension spring, when
extended, stores energy and can be
dangerous. Always use tools specifically
designed for installing or removing an extension
spring. Always compress or extend springs
slowly.
Figure 18
1. Neutral Bracket
2. Clevis
3. Speed Control Arm
1
2
3
Connect clevis
here for faster
speed range.