JLG G12-55A Service Manual - Manual (Page 96)

Transmission
6-8 G10-55A, G12-55A
2. Low or no pump flow or
pressure.
1. Low oil level. 1. Fill transmission to correct level
with hydraulic oil. Refer to
Section 2.4, “Fluid and
Lubricant Capacities.”
2. Transmission filled with incorrect
oil, or oil contaminated.
2. Drain transmission and fill to
correct level with hydraulic oil.
Refer to Section 2.4, “Fluid and
Lubricant Capacities.”
3. Pump suction pipe screen
clogged.
3. Clean, repair and/or replace
suction pipe.
4. Central shaft damaged. 4. Replace central shaft.
5. Pump worn or damaged. 5. Repair or replace pump
assembly.
3. Low clutch pressure. 1. Incorrect oil level. 1. Fill transmission to correct level
with hydraulic oil. Refer to
Section 2.4, “Fluid and
Lubricant Capacities.”
2. Main pressure valve stuck open. 2. Clean the valve spool and
housing.
3. Broken or worn coupling shaft or
piston o-rings.
3. Replace coupling and/or o-rings.
4. Pressure reducing valve stuck
open.
4. Clean the valve spool and
housing.
4. Lack of power. 1. Park or service brake dragging. 1. Refer to Section 8.4, “Hydraulic
Circuits.”
2. Low engine rpm causes
converter stall.
2. Adjust the engine rpm to
specifications. Refer to Engine
Service Manual.
3. Pump output pressure is low. 3. Refer to Section Note:, “Contact
the local distributor if internal
transmission repair is required
during the warranty period.,”
Problem 2. “Low or no pump
flow or pressure.”
4. Clutch discs worn or damaged. 4. Replace clutch discs.
5. Transmission overheating. 5. Refer to Section Note:, “Contact
the local distributor if internal
transmission repair is required
during the warranty period.,”
Problem 5. “Transmission
overheating (oil above 248° F
(120° C)).”
Problem Cause Remedy