Yanmar 4JH3BE - 3. Inspection and Servicing (KM3 P)

Chapter 7 Reduction and Reversing Gear
_3_.
l_n_s~p..;.e.;;.c.;..ti.;;.on....;;.a;...n..;.d_S.;..e;...r_v_ic.;..1_·n.:.:g;.....,
_______________________
3,4JH3(B)(C)E
3. Inspection and Servicing
3-1
Clutch case
(
1)
Check the clutch case with a test hammer for cracking.
Perform a color check when required.
If
the case is cracked, replace it.
(2)
Check for staining
on
the ·inside surface of the bearing
section.
Also, measure the inside diameter of the case.
Replace the case
if it
is worn beyond the wear limit.
3-2 Bearing
(1)
Rusting and damage.
lf
the bearing is rusted or the taper roller retainer is
damages, replace the bearing.
(2) Make sure that the bearings rotates smoothly.
If
rotation is not smooth, if there is any binding, or if
any abnormal sound is evident, replace the baring.
3-3 Gear
Check the surface, tooth face conditions and backlash of
each gear. Replace any defecf1ve part.
(1)
Tooth surface wear.
Check
the
tooth
surface
for
pitting,
abnormal
wear,dents,and cracks. Repair the lightly damaged
gears and replace heavily damaged gears.
(2)
Tooth surface contact.
Check the tooth surface contact. The amount of tooth
surface contact between the tooth crest and tooth flank
must be at least 70% of the tooth width.
(3)
Backlash.
Measure the backlash of each gear, and replace the
gear when it is worn beyond the wear limit.
mm
Maintenance
standard
Input
shaft
forward
gear
and
output shalt
forward
0.06~0.12
gear
Input
shaft
reverse
gear
0.06~0.12
and
intermediate
gear
Intermediate
gear
and
0.06~0.12
output shaft
reverse
gear
3-4 Forward and reverse large gears
(1)
Contact surface with drive cone.
Wear
limit
0.2
0.2
0.2
Visually inspect the tapered surface of the forward and
reverse large gears where they make contact with the
drive cone to check
if
any abnormal condition or sign
of overheating exists.
If
any defect is found,
replace the gear.
Tapered surface
(2)
Forward/reverse gear needle bearing.
When
an
abnormal sound is produced at the needle
bearing, visually inspect the rollers; replace the bear-
ing if the rollers are faulty.
0
c2
·'--
Rollers
3-5 Drive cone
(1) Visually inspect that part of the surface that comes
into contact with the circumferential triangular slot
to check for signs of scoring, overheating or wear.
If
deep
scoring
or
signs
of
overheating
are
found,
replace the cone.
contact
surface
Helical involute spline
(2) Check the helical involute spline for
any
abnormal
condition
on
the tooth surface, and repair or replace
the part should any defect be found.
(3)
Measure the amount of wear
on
the tapered contact
surface of the drive cone, and replace the cone when
the wear exceeds the specified limit.
Reverse
large
gear
Forward
large gear
7-40
Printed
in
]:ipan
HINSHl-H8009