BRP Johnson 4HP Service Manual page 150

GEARCASE
GEARS - SHIMMING AND ADJUSTMENT
Optimum tooth contact
The optimum tooth contact is shown in the figure.
A shim adjustment may be necessary in order to obtain the
optimum tooth contact pattern.
The backlash of the gear should be checked when
increasing or decreasing the thickness of the shim to
adjust tooth contact.
Example (1)
Incorrect top side 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 posi-
tion. 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.
8-20
Optimum tooth contact
approx. 1/3 of
tooth width
HEEL
EXAMPLE OF INCORRECT
Top side toe contact
HEEL
EXAMPLE OF INCORRECT
Top side toe contact
HEEL
approx.
1 mm
TOE
TOE
TOE