
70
Twin Disc, Incorporated
Troubleshooting
Marine Transmission Service Manual #1020667
Table. 8. Troubleshooting Chart (continued)
Symptom
Cau se
Remedy
6.
No neutral.
6-1
Clutch plates warped.
6-1
Remove clutch plates.
O verhaul unit.
6-2
Control valve incorrectly
indexed.
6-2
Check and adjust control
linkage.
6-3
Solenoid malfunction
(units equipped with
electric selector valve)
6-3
Replace defective
solenoid.
6-4
Hydraulic lock piston
stuck (units equipped with
electric selector valve
and hydraulic lock).
6-4
Inspect, repair, or replace
hydraulic lock spool.
7.
Harsh engagement.
7-1
Regulating piston or rate-
of-rise piston stuck.
7-1
Disassemble control
valve. Clean parts.
Replace parts if
necessary.
7-2
Orifice plate ball in
control valve not seating
properly.
7-2
Remove orifice plate
cover. Clean parts.
Replace parts if
necessary.
7-3
Blown gasket on either
side of orifice plate.
7-3
Replace gasket.
8.
Low lube oil pressure.
8-1
Pump flow output too low.
8-1
Replace pump.
8-1
Pump suction strainer
plugged.
8-2
Remove, clean, inspect,
and install the suction
screen.
8-3
Air leak on suction side of
pump.
8-3
Inspect and correct
cause of suction leaks.
8-4
Lube relief valve
malfunction.
8-4
Remove and clean or
replace parts as
necessary.
8-5
Broken piston rings.
8-5
Replace damaged piston
rings.
9.
Oil spilling out of
breather.
9-1
Oil level too high.
9-1
Adjust oil level.
9-2
Wrong type of oil.
9-2
Draw and refill with
recommended oil.
Symptom
Cau se
Remedy
6.
No neutral.
6-1
Clutch plates warped.
6-1
Remove clutch plates.
O verhaul unit.
6-2
Control valve incorrectly
indexed.
6-2
Check and adjust control
linkage.
6-3
Solenoid malfunction
(units equipped with
electric selector valve)
6-3
Replace defective
solenoid.
6-4
Hydraulic lock piston
stuck (units equipped with
electric selector valve
and hydraulic lock).
6-4
Inspect, repair, or replace
hydraulic lock spool.
7.
Harsh engagement.
7-1
Regulating piston or rate-
of-rise piston stuck.
7-1
Disassemble control
valve. Clean parts.
Replace parts if
necessary.
7-2
Orifice plate ball in
control valve not seating
properly.
7-2
Remove orifice plate
cover. Clean parts.
Replace parts if
necessary.
7-3
Blown gasket on either
side of orifice plate.
7-3
Replace gasket.
8.
Low lube oil pressure.
8-1
Pump flow output too low.
8-1
Replace pump.
8-1
Pump suction strainer
plugged.
8-2
Remove, clean, inspect,
and install the suction
screen.
8-3
Air leak on suction side of
pump.
8-3
Inspect and correct
cause of suction leaks.
8-4
Lube relief valve
malfunction.
8-4
Remove and clean or
replace parts as
necessary.
8-5
Broken piston rings.
8-5
Replace damaged piston
rings.
9.
Oil spilling out of
breather.
9-1
Oil level too high.
9-1
Adjust oil level.
9-2
Wrong type of oil.
9-2
Draw and refill with
recommended oil.
Summary of Contents for MG-5170DC
Page 3: ...Document Number 1020667 July 2002 Marine Transmission Service Manual ...
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Page 108: ...108 Twin Disc Incorporated Disassembly Marine Transmission Service Manual 1020667 ...
Page 114: ...114 Twin Disc Incorporated Cleaning and Inspection Marine Transmission Service Manual 1020667 ...
Page 166: ...166 Twin Disc Incorporated Assembly Marine Transmission Service Manual 1020667 ...
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Page 206: ...206 Twin Disc Incorporated Special Tools Marine Transmission Service Manual 1020667 Notes ...
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Page 208: ...208 Twin Disc Incorporated Special Tools Marine Transmission Service Manual 1020667 Notes ...
Page 224: ...224 Twin Disc Incorporated Illustrations Marine Transmission Service Manual 1020667 Notes ...
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Page 226: ...226 Twin Disc Incorporated Illustrations Marine Transmission Service Manual 1020667 Notes ...
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Page 228: ...228 Twin Disc Incorporated Illustrations Marine Transmission Service Manual 1020667 Notes ...
Page 230: ...230 Twin Disc Incorporated Engineering Drawings Marine Transmission Service Manual 1020667 ...
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Page 247: ...CAUTION ...
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