Symptom
Possible cause
Remedy
13. Transmission noise becomes lou-
der.
13.1 Fluid level too low so that pump
sucks in air.
13.2 Damage starting on flexible coupling
due to wear or fatigue, possible due
to misalignment between engine
and transmission.
13.3 Beginning damage of bearings in
transmission, e.g. due to torsionalvi-
brations, running without fluid, over-
load, wrong alignment of transmis-
sion excessive engine output.
13.4 Beginning damage of gearings, e.g.
due to torsionalvibrations, running
without fluid, overload.
13.5 Fluid suction pipe in transmission
has come Ioose.
13.1 Top up with fluid to marking on dip-
stick.
13.2 Replace flexible coupling.
Check alignment between engine
and transmission.
13.3 Disassemble transmission, replace
bearings concerned and other faulty
parts. Find causes and remedy.
13.4 Disassemble transmission, remove
faulty parts.
13.5 Disassemble transmission, fix fluid
suction pipe.
14. Chattering transmission noise
mainly at low engine.
14.1 The engine or propeller generate tor-
sionalvibrations in the drive unit
which produce a "chattering" noise
in the transmission.
14.2 Misaligned cardan shafts on input or
output.
14.1 Mount a flexible coupling with another
stiffness factor between enging and
transmission; a coupling with a higher
stiffness factor might be sufficient.
Otherwise analyse the torsional vibra-
tions to find out the required stiffness
for the coupling.
14.2 Mount and align cardan shaft strictly
according to instructions issued by
cardan shaft manufacture.
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.
37
Repair Manualand Spare Parts List
Section 9
