TM 5-3810-300-24&P-3
1.2.2 EXHAUST VALVES
upper end. They replace the former 45 chamfered
valve guides.
Remove Exhaust Valve Guide
1. Support the cylinder head, bottom side up, on 2"
thick wood blocks.
2. Drive the valve guide out from the bottom of the
cylinder head with tool J 6569.
Install Exhaust Valve Guide
Place the cylinder head right side up on an arbor press
and install the valve guide as follows:
1. Insert the internally threaded end of the valve
guide in the proper valve guide installing tool
(refer to chart). Be sure to use the correct tool
to avoid damage to the valve guide, and to
locate the valve guide to the proper dimension.
Fig. 6 - Cleaning Exhaust Valve Guide
When replacing valve guides, the current guide
which is machined for use with a valve guide
the valve guides evidence hot operation due to
seal should be used in place of the 45
overloads, inadequate cooling, or improper timing which
chamfered valve guide (Fig. 7). The current
results in carbonization of the lubricating oil.
guide will facilitate field installation of valve
guide seals when it is felt their use will be
Clean the carbon from the valve stems and wash the
beneficial.
valves with fuel oil. The valve stems must be free from
scratches or scuff marks and the valve faces must be
free from ridges, cracks, or pitting. If necessary, reface
CAUTION: Be sure to use the correct installing tool,
the valves or install new valves. If the valve heads are
otherwise damage to the valve guide will result.
warped, replace the valves.
If there is evidence of engine oil running down the
exhaust valve stem into the exhaust chamber, creating a
high oil consumption condition because of excessive
idling and resultant low engine exhaust back pressure,
install valve guide oil seals.
Inspect Exhaust Valve Guides
Clean the inside diameter of the valve guides with brush
J 5437 (Fig. 6). This brush will remove all gum or
carbon deposits from the guides, including the spiral
grooves.
Inspect the valve guides for fractures, chipping, scoring,
or excessive wear. Check the valve-to-guide clearance,
since worn valve guides may eventually result in
improper valve seat contact. If the clearance exceeds
Fig. 7 - Former and Current Valve Guides Used in
005", replace the valve guides.
Cylinder Head
The current valve guides (Fig. 7) are machined at the
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