2009 YAMAHA YZ450F transmission oil

4-57
CRANKCASE AND CRANKSHAFT
• Crank width "d"
Out of specification→Replace.
Use the dial gauge and a thick-
ness gauge.
CHECKING THE OIL STRAINER
1. Inspect:
• Oil strainer
Damage→Replace.
INSTALLING THE CRANKCASE
BEARING
1. Install:
• Bearing
• Bearing stopper
• Bolt (bearing stopper) • Screw (bearing stopper)
• Screw [bearing stopper (crank-
shaft)] "1"
To left and right crankcase.
• Install the bearing by pressing its
outer race parallel.
• To prevent the screw [bearing stop-
per (crankshaft)] from becoming
loose, crush the screw head periph-
ery "a" into the concave "b" using a
punch etc. In so doing, take care
not to damage the screwdriver re-
ceiving hole in the screw head.
INSTALLING THE CRANKSHAFT
1. Install:
• Crankshaft "1"
Use the crankshaft installing tool
"2", "3", "4" and "5".
• Hold the connecting rod at top dead
center with one hand while turning
the nut of the installing tool with the
other. Operate the installing tool un-
til the crankshaft bottoms against
the bearing.
• Before installing the crankshaft,
clean the contacting surface of
crankcase.
Do not use a hammer to drive in
the crankshaft.
A. For USA and CDN
B. Except for USA and CDN
2. Check:
• Shifter operation
• Transmission operation
Unsmooth operation→Repair.
3. Install:
• Oil strainer "1"
• Bolt (oil strainer) "2"
4. Apply:
•Sealant
On the right crankcase.
Clean the contacting surface of left
and right crankcase before applying
the sealant.
Dial gauge and stand:
YU-3097/90890-01252
Standard
Runout
limit:0.03 mm
(0.0012 in)0.05 mm
(0.002 in)
Small
end
free
play:0.4–1.0 mm
(0.016–0.039
in)2.0 mm
(0.08 in)
Side
clear-
ance:0.15–0.45
mm (0.0059–
0.0177 in)0.50 mm
(0.02 in)
Crack
width:61.95–62.00
mm (2.439–
2.441 in)—
Bolt (bearing stopper):
10 Nm (1.0 m•kg, 7.2
ft•lb)
Screw (bearing stopper):
10 Nm (1.0 m•kg, 7.2
ft•lb)
Screw [bearing stopper
(crankshaft)]:
14 Nm (1.4 m•kg, 1.0
ft•lb)
Crankshaft installing pot
"2":
YU-90050/90890-01274
Crankshaft installing bolt
"3":
YU-90050/90890-01275
Adapter (M12) "4":
YU-90063/90890-01278
Spacer (crankshaft in-
staller) "5":
YM-91044/90890-04081
Bolt (oil strainer):
10 Nm (1.0 m•kg, 7.2
ft•lb)
YAMAHA Bond No. 1215
(ThreeBond
® No.1215):
90890-85505

4-58
CRANKCASE AND CRANKSHAFT
5. Install:
• Dowel pin "1"
• O-ring "2"
• Right crankcase
To left crankcase.
• Apply the lithium soap base grease
on the O-ring.
• Fit the right crankcase onto the left
crankcase. Tap lightly on the case
with soft hammer.
• When installing the crankcase, the
connecting rod should be posi-
tioned at TDC (top dead center).
6. Tighten:
• Bolt (hose guide) "1"
• Bolt (crankcase)
Tighten the crankcase tightening
bolts in stage, using a crisscross pat-
tern.
7. Install:
• Timing chain
• Timing chain guide (intake side)
• Bolt (timing chain guide)
8. Remove:
• Sealant
Forced out on the cylinder mating
surface.9. Apply:
• Engine oil
To the crank pin, bearing and oil
delivery hole.
10. Check:
• Crankshaft and transmission op-
eration.
Unsmooth operation→Repair.
Bolt (crankcase):
12 Nm (1.2 m•kg, 8.7
ft•lb)
Bolt (timing chain guide):
10 Nm (1.0 m•kg, 7.2
ft•lb)

4-60
TRANSMISSION, SHIFT CAM AND SHIFT FORK
REMOVING THE TRANSMISSION
1. Remove:
• Main axle "1"
•Drive axle "2"
•Shift cam
• Shift fork 3
• Shift fork 2
• Shift fork 1
• Remove assembly with the collar
"3" installed to the crankcase.
• Remove assembly carefully. Note
the position of each part. Pay partic-
ular attention to the location and di-
rection of shift forks.
• Remove the main axle, drive axle,
shift cam and shift fork all together
by tapping lightly on the transmis-
sion drive axle with a soft hammer.
CHECKING THE GEARS
1. Inspect:
• Matching dog "a"
• Gear teeth "b"
• Shift fork groove "c"
Wear/damage→Replace.
2. Inspect:
• O-ring "1"
Damage→Replace.
3. Check:
• Gears movement
Unsmooth movement→Repair or
replace.
CHECKING THE BEARING
1. Inspect:
• Bearing "1"
Rotate inner race with a finger.
Rough spot/seizure→Replace.CHECKING THE SHIFT FORK,
SHIFT CAM AND SEGMENT
1. Inspect:
• Shift fork "1"
Wear/damage/scratches→Re-
place.
2. Inspect:
• Shift cam "1"
• Segment "2"
Wear/damage→Replace.
3. Check:
• Shift fork movement
Unsmooth operation→Replace
shift fork.
For a malfunctioning shift fork, re-
place not only the shift fork itself but
the two gears each adjacent to the
shift fork.
INSTALLING THE TRANSMISSION
1. Install:
• 5th pinion gear (21T) "1"
• 3rd pinion gear (18T) "2"
•Collar "3"
• 4th pinion gear (22T) "4"
• 2nd pinion gear (15T) "5"
To main axle "6".
Apply the molybdenum disulfide oil
on the inner and end surface of the
idler gear and on the inner surface of
the sliding gear, then install.
2. Install:
•Collar "1"
• 2nd wheel gear (23T) "2"
• 4th wheel gear (24T) "3"
• 3rd wheel gear (23T) "4"
• 5th wheel gear (20T) "5"
•Collar "6"
• 1st wheel gear (27T) "7"
• O-ring "8"
To drive axle "9".
• Apply the molybdenum disulfide oil
on the inner and end surface of the
idler gear and on the inner surface
of the sliding gear, then install.
• Apply the lithium soap base grease
on the O-ring.
3. Install:
• Washer "1"
• Circlip "2"

4-61
TRANSMISSION, SHIFT CAM AND SHIFT FORK
• Be sure the circlip sharp-edged cor-
ner "a" is positioned opposite side
to the washer and gear "b".
• Install the circlip with its ends "c"
settled evenly on the spline crests.
4. Install:
•Collar "1"
• Apply the lithium soap base grease
on the oil seal lip.
• When installing the collar into the
crankcase, pay careful attention to
the crankcase oil seal lip.
5. Install:
• Shift fork 1 (L) "1"
• Shift fork 2 (C) "2"
• Shift fork 3 (R) "3"
•Shift cam "4"
To main axle and drive axle.
• Apply the molybdenum disulfide oil
on the shift fork grooves.
• Apply engine oil to the shift cam
groove, bearing contact surface
and shift fork shaft.
• Mesh the shift fork #1 (L) with the
4th wheel gear "5" and #3 (R) with
the 5th wheel gear "7" on the drive
axle.
• Mesh the shift fork #2 (C) with the
3rd pinion gear "6" on the main ax-
le.
6. Install:
• Transmission assembly "1"
To left crankcase "2".
Apply the engine oil on the bearings
and guide bars.
7. Check:
• Shifter operation
• Transmission operation
Unsmooth operation→Repair.