Checking The Lower Unit For Air Leakage - Yamaha 55DEHD Service Manual

3. Check the oil for metal, discoloration and
its viscosity. Check the internal parts of
the lower case if necessary.
4. Fully tilt the outboard motor down.
5. Insert a gear oil tube into the drain hole
and slowly fill the gear oil until oil flows
out of the check hole and no air bubbles
are visible.
Recommended gear oil:
Hypoid gear oil
API: GL-4
SAE: 90
Oil quantity:
610 cm 3
(20.62 US oz, 21.51 Imp oz)
6. Install the new gaskets 3, check screw
2, drain screw 1 quickly, and then tight-
en them to the specified torque.
Check screw 2 and drain screw 1:
9 N·m (0.9 kgf·m, 6.6 ft·lb)
6885J11
3
2
3
1
69D10056
Checking the lower unit for air leak-
age
cC
Do not over pressurize the lower unit, oth-
erwise the oil seals may be damaged.
1. Remove the check screw 1, and then
install the special service tool 2.
Leakage tester 2: 90890-06840
2. Apply the specified pressure to check
that the pressure is maintained in the
lower unit for at least 10 seconds.
NOTE:
Cover the check hole with a rag when remov-
ing the special service tool from the lower
unit.
Lower unit holding pressure:
70 kPa (0.7 kgf/cm
3. If the pressure is not maintained, check
the drive shaft, propeller shaft, oil seals,
O-rings of propeller shaft housing, shift
rod oil seal, and gasket of drain screw.
Replace if damaged.
Check screw 1:
9 N·m (0.9 kgf·m, 6.6 ft·lb)
Bracket / Lower unit
1
2
6G430430
2 , 14 psi)
3-18
1
2
3
4
5
6
7
8
9