TROUBLESHOOTING
SERVICE MANUAL NUMBER 22
90-860074--1 FEBRUARY 2002
Page 1C-39
ZF / Hurth Hydraulic Transmission (continued)
Trouble
Possible Cause
Remedy
15. Transmission
noise changes,
becomes louder
15. A. Fluid level too low so
that pump sucks in air
15. A. Top off fluid to fill mark
B. Damage starting on
flexible coupling due to
wear or fatigue, possible
due to misalignment
between engine and
transmission
B. Replace flexible
coupling. Check alignment
between engine and
transmission
C. Beginning damage of
bearings in transmission;
torsional vibrations,
running without fluid,
overload, wrong alignment
of transmission, excessive
engine output
C. Disassemble
transmission, replace
bearings concerned and
other faulty parts
D. Beginning damage of
gearings; torsional
vibrations, running
without, fluid, overload
D. Disassemble
transmission, remove
faulty parts
E. Fluid baffle on
transmission has come
loose
E. Disassemble
transmission,attach baffle
plate
F. Fluid suction pipe in
transmission has come
loose
F. Disassemble
transmission, fix fluid
suction pipe
16. Chattering
transmission noise
mainly at low
speed
16. A. The engine or
propeller generate
torsional vibrations, which
produce a chattering noise
in the transmission
16. A. Mount a flexible
coupling with another
stiffness factor between
engine and transmission;
a coupling with a higher
stiffness factor might be
sufficient
B. Misaligned cardan
shafts on input or output
shafts
B. Mount and align
cardan shaft strictly
according to instructions
issued by cardan shaft
manufacturer