LOWER UNIT 9-25
Concave side
Convex side
Heel
Tooth top
Tooth bottom
Tooth width
Toe
TOOTH
CONTACT
PATTERN
Optimum tooth contact
HEEL
Convex side
TOE
approx. 1/3 of
tooth width approx.
1 mm
EXAMPLE OF INCORRECT
Top side toe contact
HEEL
TOE
EXAMPLE OF INCORRECT
Bottom side toe contact
HEEL
TOE
Push
2. Install the propeller shaft and the housing assembly (minus
the reverse gear and the internal components).
3. Push the propeller shaft inward and hold in position.
4. Using the driveshaft holder, rotate the driveshaft 5 – 6 times.
"
09921-28710: Driveshaft holder
5. Carefully pull out the propeller shaft and the housing to
check the tooth contact pattern.
Optimum tooth contact
The optimum tooth contact is shown in the figure.
A shim adjustment may be necessary to obtain the optimum
tooth contact pattern.
#
The backlash of the gear should be checked when in-
creasing or decreasing the thickness of the shim to
adjust tooth contact.
Example (1)
Incorrect topside toe contact:
Correction measures:
• Decrease the thickness of the forward gear shim.
• Slightly increase the pinion gear shim thickness.
#
Do not set tooth contact in the top side toe contact po-
sition. Damage and chipping of the forward and pinion
gear may result.
Example (2)
Incorrect bottom side toe contact:
Correction measures:
• Increase the thickness of the forward gear shim.
• Slightly decrease the pinion gear shim thickness.
#
Do not set tooth contact in the bottom side toe contact
position. Chipping of the pinion gear may result.