Yanmar 3JH4E Service Manual page 125

(I) Low clutch oil pressure
(clutch slips)
(IV) Difficulty changing into forward,
neutral, and reverse
(I) Low clutch oil pressure (clutch slips)
No.
1 Clogging of filter on suction side.
2 Worn oil pump.
3 Sticking of oil pressure adjustment valve.
4 Damage or old oil pressure adjustment valve
spring.
5 Damaged seal ring.
6 Incorrect positioning of forward/reverse
conversion valve.
7 Worn sliding parts of forward/reverse conversion
valve.
8 Damaged O-ring, V-ring in oil pressure pipe.
9 Low speed valve handle slips.
10 Poor assembly of low speed valve handle.
11 Insufficient oil.
(II) Overheating
No.
1 Clutch slippage due to low oil pressure.
2 Clutch slippage due to overloading.
3 Damaged bearing.
4 Too much oil.
5 Problem with oil cooler.
6 Poor quality or inappropriate oil.
7 Poor operation of low speed valve.
(III) Abnormal noise
No.
1 Excessive backlash of gear.
2 Damaged bearing.
3 Abnormal vibration.
TROUBLE WITH MARINE GEAR
(II) Overheating
Cause and effect
Cause and effect
Cause and effect
(III) Abnormal noise
(V) Dragging
Countermeasure
Disassemble and clean.
Repair or replace.
Repair or replace.
Replace.
Repair.
Adjust.
Replace.
Replace.
Adjust to correct position.
Reassemble.
Check for oil leakage and replenish.
Countermeasure
Review (I-1, I-11).
Reduce load.
Replace.
Check oil level and adjust.
Check water level and adjust.
Change oil.
Review manual.
Countermeasure
Replace.
Replace.
Eliminate dangerous rotation.
105
3. Troubleshooting
(VI) Abnormal lube
oil pressure