TOHATSU MD 70-90C2 Service Manual page 206

Lower Unit
7. Select proper thickness of shim based on the backlash
measured with dial gauge and on the table shown.
· Confirm dial gauge reading and adjust backlash
by using thickness of shim selected.
· Measure backlash several times while changing
gear teeth contact position.
· When measuring backlash, make drive shaft
pulling up force equal among the measurements.
· This work can be made easier when the
opening of gear case of propeller shaft side is
faced upward and fixed horizontally with a
holder.
Proper Backlash :
0.67 - 0.94 mm (0.0264 - 0.0370 in)
Add shim a into the gap between forward (A) gear t and
8.
taper roller bearing y if necessary.
For removal or installation of taper roller
bearing, refer to;
"Disassembly of Forward (A) Gear" or
"Assembly of Forward (A) Gear"
respectively.
Types of Shims a :
0.1 mm (0.0039 in) P/N. 3B7-64016-0
0.15 mm (0.0059 in) P/N. 3B7-64015-0
6-36
CAUTION
Dial Gauge Reading : mm (in)
（0.0157∼0.0213）
0.40∼0.54
0.55∼0.66 （0.0217∼0.0260）
0.67∼0.94 （0.0264∼0.0370）
0.95∼1.06 （0.0374∼0.0417）
（0.0421∼0.0488）
1.07∼1.24
1.25∼1.41 （0.0492∼0.0555）
1.42∼1.59 （0.0559∼0.0626）
1.60∼1.77 （0.0630∼0.0697）
（0.0701∼0.0764）
1.78∼1.94
1.95∼2.12 （0.0768∼0.0835）
2.13∼2.30 （0.0839∼0.0906）
2.31∼2.47 （0.0909∼0.0972）
（0.0976∼0.1043）
2.48∼2.65
a
y
Shim Thickness : mm (in )
+ means addition of shim/-
means removal of shim
−0.10 （0.0039）
−0.05 （0.0019）
0.00
＋0.05 （0.0019）
＋0.10 （0.0039）
＋0.15 （0.0059）
＋0.20 （0.0078）
＋0.25 （0.0098）
＋0.30 （0.0118）
＋0.35 （0.0137）
＋0.40 （0.0157）
＋0.45 （0.0177）
＋0.50 （0.0196）
Shim
t
TLDI 75/90C2 2010