Symptom
Possible cause
Remedy
13. Transmission noise becomes
louder.
13.1 Fluid level too low so that pump
sucks in air.
13.2 Damage starting on flexible coupling
due to wear or fatigue probably due
to misalignment between engine
and transmission.
13.3 Beginning damage of bearings in
transmission, e.g. due to torsional
vibration, running without fluid,
overload, wrong alignment of
transmission.
13.4 Beginning damage of gearing, e.g.
due to torsionalvibrations, running
without fluid, overload.
13.5 Fluid suction pipe in transmission
has come loose.
13.1 Top up with fluid to marking on dip-
stick.
13.2 Replace flexible coupling. Cheek
alignment between engine and
transmission.
13.3 Disassemble transmission, replace
bearings concerned and other faulty
parts. Find causes and remedy.
13.4 Disassemble transmission, replace
faulty parts.
13.5 Disassemble transmission fix fluid
suction pipe.
14. Chattering transmission noise
mainly at low engine speed.
14.1 The engine or propeller generates
torsionalvibrations in the drive unit
which produces a hammering noise
in the transmission.
14.2 Misaligned cardan shafts on input or
output.
14.1 Mount a flexible coupling with a dif-
ferent stiffness factor between en-
gine and transmission; a coupling
with a higher stiffness factor might
be sufficient. Otherwise analyze the
torsionalvibrations to find out the re-
quired stiffness for the coupling.
14.2 Mount and align cardan shaft strictly
according to instructions issued by
cardan shaft manufacturer.
15. Low pressure.
15.1 Fine filter is dirty.
15.2 Fluid level in transmission is low.
15.3 Controlblock is broken.
15.4 Problem at control valve.
15.5 Piston rings on input shaft
are faulty.
15.6 Piston rings inside the clutch
are faulty.
15.7 Defective cover filter : air suction.
15.8 Oilsuction hose not properly
adjusted.
15.9 Fitting key in input shaft for fluid
pump drive is broken.
15.10 Possible wear of the piston ring
grooves.
15.1 Replace fine filter.
15.2 Refill with fluid.
15.3 Replace control block.
15.4 Replace control block.
15.5 Remove control block and replace
piston rings.
15.6 Disassemble transmission, replace
piston rings.
15.7 Replace cover filter.
15.8 Replace the seal and adjust cor-
rectly the suction hose.
15.9 Remove control block replace fit-
ting key, replace any other faulty
parts.
15.10 Replace the input shaft.
16. Oilleakage.
16.1 Porosity.
16.2 Seals.
16.3 Joints.
16.4 Bracket with flatness error.
16.5 Bolts are not tight.
16.6 Fittings loosen.
16.7 Dipstick is not tight.
16.8 Filter is not tight.
16.9 Excessive fluid in transmission.
16.10 Breather clogged with paint or dirt
(fluid leakage at output shaft).
16.11 Aluminium washers used more
times.
16.1 Replace faulty parts.
16.2 Replace seals.
16.3 Check if bolts are tighten with the
correct torque. Clean the surface
and resealwith Loctite 518.
16.4 Replace bracket.
16.5 Resealand tighten bolts with pre-
scribed torque.
16.6 Tighten or replace.
16.7 Tighten dipstick or replace o-ring
dipstick.
16.8 Tighten filter or replace o-ring filter
16.9 Remove excessive fluid with com-
mercialsuction pump.
16.10 Remove paint or dirty from
breather.
16.11 Replace aluminium washers.
33
Repair Manualand Spare Parts List
Section 9
