TM 5-3805-280-24-2
Cylinder Head and Valves
CHECK AND ADJUST VALVE CLEARANCE
05
10
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.
A--Timing/Rotation Hole
IMPORTANT: Visually inspect contact surfaces of
B--Timing Pin Hole
valve tips 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).
NOTE: Some engines are equipped with flywheel
housings which do not allow use of an engine
flywheel rotation tool. These engines may be
rotated from front nose of engine, using JDG966
Crankshaft Rotation Tool.
3. Using JDE83 or JDG820 Flywheel Turning Tool, rotate
engine flywheel in running direction (clockwise viewed
from front) until No. 1 cylinder is at "TDC" Compression
stroke. Insert 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.
Continued on next page
RG,05,DT7375 1911NOV971/5
13-68
