TOHATSU BFT115A Service Manual page 595

Attach the special tool to the vertical shaft (1) as shown,
adjust the dial indicator (2) so its needle is at the line "2"
of the backlash indicator tool.
TOOLS:
Backlash indicator tool (3)
Backlash indicator
attachment (4)
Turn the vertical shaft lightly right and left and record
the dial indicator reading.
Measure the backlash at four points (by turning the
vertical shaft in increments of 90°) in the same manner.
• When measuring the backlash, do not turn the
propeller shaft by turning the vertical shaft.
Obtain the forward bevel gear backlash using the dial
indicator runout and the following formula.
Formula:
Backlash = Dial gauge runout ÷ 0.86
Example:
When dial gauge runout is 0.175 mm (0.0069 in),
Backlash =
0.175 mm (0.0069 in) ÷ 0.86 = 0.20 mm (0.008 in)
STANDARD VALUE:
0.10 – 0.30 mm (0.004 – 0.012 in)
If the backlash is too large compared to the standard
value, increase the forward bevel gear shim thickness
and recheck the backlash.
If the backlash is too small compared to the standard
value, reduce the forward bevel gear shim thickness
and recheck the backlash.
• Be sure to use the special tool when removing the
bearings in order to readjust the backlash.
• After adjusting the forward bevel gear shim, perform
the propeller shaft thrust clearance inspection/
adjustment (page 17-51).
GEAR CASE (COUNTER ROTATION)
07SPJ-ZW0030Z
90°
07WPK-ZW50100
90°
(1)
90°
90°
(3)
(2)
(4)
17-49