SELVA MARINE Blue Whale 250 EFI Service Manual page 220

LOWR
4. Install the backlash indicator onto the
drive shaft (22.4 mm [0.88 in] in diame-
ter), then the dial gauge.
NOTE:
Install the dial gauge so that the plunger a
contacts the mark b on the backlash indica-
tor rod.
Backlash indicator 4: 90890-06706
Magnet base plate 5: 90890-07003
Dial gauge set 6: 90890-01252
Magnet base B 7: 90890-06844
5. Slowly turn the drive shaft clockwise and
counterclockwise and measure the back-
lash when the drive shaft stops in each
direction.
Forward gear backlash:
0.32–0.55 mm (0.0126–0.0216 in)
6. Add or remove shim(s) if out of specifica-
tion.
Forward gear
backlash
Less than
0.32 mm (0.0126 in)
More than
0.55 mm (0.0216 in)
M: Measurement
6-29
Lower unit
Shim thickness
To be decreased by
(0.44 – M) × 0.71
To be increased by
(M – 0.44) × 0.71
Available shim thicknesses:
0.10, 0.12, 0.15, 0.18, 0.30, 0.40, and
0.50 mm
7. Remove the special service tools from
the propeller shaft.
8. Apply a load to the reverse gear by
installing the propeller 7, the spacer 8
(without the washer 9), then the washer
0 as shown.
NOTE:
Tighten the propeller nut A while turning the
drive shaft until the drive shaft can no longer
be turned.
9. Slowly turn the drive shaft clockwise and
counterclockwise and measure the back-
lash when the drive shaft stops in each
direction.
Reverse gear backlash:
0.32–0.65 mm (0.0126–0.0256 in)
6P23H11