TOHATSU BFT115A Service Manual page 596

GEAR CASE (COUNTER ROTATION)
REVERSE BEVEL GEAR BACKLASH
Backlash adjustment must be made after adjustment of
each gear shim (page 17-40).
Install the following parts except the water pump.
– Vertical shaft (page 17-32)
– Propeller shaft holder (page 17-21)
– Shift rod (page 17-18)
Wrap a shop towel (1) around the shift rod (2) spline,
and use pliers to turn the shift rod in the direction shown
(cutout (3) of the shift rod spline is toward the left side of
the cruising direction (4)).
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 reverse 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 – 0.35 mm (0.004 – 0.014 in)
If the backlash is too large compared to the standard
value, increase the reverse bevel gear shim thickness
and recheck the backlash.
If the backlash is too small compared to the standard
value, reduce the reverse 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.
17-50
Viewed from the upper side:
90°
07SPJ-ZW0030Z
07WPK-ZW50100
90°
(2)
(4)
(3)
(1)
90°
90°
(3)
(2)
(1)
(2)
(4)