John Deere POWERTECH 4045 - Manual (Page 172)

Lubrication & Maint./2000 Hour/24 Month
OUO1089,0000208 –19–27JUL06–1/5
Check and Adjust Valve Clearance
(4045HF475 And 6068HF475 Engines)
RG12168
–UN–03JUL02
Flywheel Housing Timing Holes
A—Timing/Rotation Hole
B—Timing Pin Hole
CAUTION: To prevent accidental starting of
engine while performing valve adjustments,
always disconnect NEGATIVE (—) battery
terminal.
IMPORTANT: Valve clearance MUST BE checked and
adjusted with engine COLD.
1. Remove rocker arm cover and crankcase ventilator
tube.
IMPORTANT: Visually inspect contact surfaces of
valve tips, bridges and rocker arm wear
pads. Check all parts for excessive
wear, breakage, or cracks. Replace
parts that show visible damage.
Rocker arms that exhibit excessive
valve clearance should be inspected
more thoroughly to identify damaged
parts.
2. Remove plastic plugs or cover plate from engine
timing/rotation hole (A) and timing pin hole (B).
NOTE: Some engines are equipped with flywheel
housings which do not allow use of an engine
flywheel rotation tool. These engines with straight
nose crankshafts may be rotated from front nose
of engine, using JDG966 Crankshaft Front/Rear
Rotation Adapter.
3. Using JDE83 or JDG820 Flywheel Turning Tool, rotate
engine flywheel in running direction (clockwise viewed
from front) until No. 1 (front) cylinder is at TDC
compression stroke. Insert JDG1571 or JDE81-4
Timing Pin in flywheel.
If No. 1 cylinder rocker arms are loose, the engine is at
No. 1 TDC compression.
If No. 1 cylinder rocker arms are not loose, rotate
engine one full revolution (360
°
) to No. 1 TDC
compression.
35-12
080706
PN=170
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