Measuring The Middle Gear Backlash

MIDDLE GEAR

EAS25880                                                  EAS25900

MEASURING THE MIDDLE GEAR                                 ADJUSTING THE MIDDLE GEAR BACKLASH
BACKLASH                                                  1. Loosen:
1. Measure:                                                • Middle driven shaft bearing housing bolts
 • Middle gear backlash                                   2. Remove:
   Out of specification → Refer to “ADJUSTING              • Middle driven pinion gear shim(s)
   THE MIDDLE GEAR BACKLASH” on page                      3. Tighten:
   5-91.                                                   • Middle driven shaft bearing housing bolts

           Middle gear backlash                                           Middle driven shaft bearing hous-
            0.10–0.20 mm (0.0039–0.0079 in)                      T.
                                                                     R.
                                                                          ing bolt
                                                                            25 Nm (2.5 m·kg, 18 ft·lb)
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Hold the middle drive shaft “1”.                       ECA14050

b. Install the gear lash measurement tool “2” as          CAUTION:
   shown.                                                 Do not overtighten the middle driven shaft
c. Make sure the dial gauge plunger contacts              bearing housing bolts or you may obtain too
   the measuring point “a” on the gear lash mea-          little middle gear backlash and damage the
   surement tool as shown.                                middle gears. If the bolts are overtightened,
                                                          loosen them until the crankcase-to-middle-
           Gear lash measurement tool                     driven-shaft-bearing-housing clearance is
            90890-01467                                   within specification, as stated below. Then,
            YM-01467
                                                          repeat all of the previous steps.
                                                      NOTE:
                                                          • Tighten the middle driven shaft bearing hous-
                                                            ing bolts carefully, one thread turn at a time
                                                            only. Push in the middle driven shaft bearing
                                                            housing and then tighten the bolts to specifica-
                                                            tion.
                                                          • After tightening the middle driven shaft bearing
                                                            housing bolts, loosen them until the clearance
                                                            between the crankcase and the housing is ap-
                                                            proximately 2 mm (0.08 in), when measured
                                                            with a thickness gauge “1”.

  a. 14 mm (0.55 in)
d. While gently turning the middle driven shaft           4. Hold the middle drive shaft.
   back and forth, measure the middle gear                5. Turn:
   backlash.                                               • Middle driven shaft
NOTE:                                                 NOTE:
Measure the middle gear backlash at four posi-            While carefully tightening the middle driven shaft
tions. Rotate the middle driven shaft 90° each            bearing housing bolts in stages and in a criss-
time and observe the reading on the dial gauge.           cross pattern, turn the middle driven shaft back
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲                          and forth until the dial gauge reads 0.10–0.20
                                                          mm (0.0039–0.0079 in).

                                                   5-91