TM 5-2420-230-24-2
B3.9 and B5.9 Series Engines
Overhead Set (003-004)
Section 3 - Rocker Levers - Group 03
Page 3-3
Loose rocker levers and the need to reset the valve clear-
ance frequently can also indicate camshaft lobe or tappet
wear. If an inspection of the rocker levers, valve stems, and
push tubes does not show wear, then tappet and/or cam-
shaft lobe wear can be suspected. Refer to Procedures
001-008 and 004-015.
CAUTION
Anytime a new camshaft is installed, new tappets and
push tubes must also be installed. Failure to do so can
cause severe engine damage.
The camshaft lobes can be inspected after removing the
lubricating oil pan.
The tappets can also be inspected with the lubricating oil
pan removed. Remove the push tubes, lift the tappets, and
inspect the tappet faces.
Severely damaged camshaft journal(s) can generate metal
chips that will be found in the lubricating oil pan and oil
filter.
NOTE: As the clearance between the camshaft bushing(s)
and camshaft journal(s) increase, oil pressure and volume
will decrease, causing damage to the camshaft and tappets.
Adjust (003-004-029)
1/2-Inch Drive, Engine Barring Tool, Part No. 3824591
Locate top dead center (TDC) for cylinder No. 1 by barring
the crankshaft slowly while pressing on the engine timing
pin. Barring the engine is recommended from the flywheel
on the rear of the engine.
L-831