TM 5-3895-346-14
PREVENTATIVE MAINTENANCE
ENGINE OVERHAUL
Item 27 Crankcase Pressure
Check and record the crankcase pressure every 36 months or 60,000 miles (2000 hours) (refer to
Troubleshooting (Engine)).
Item 28 Air Box Check Valves
Every 100,000 miles or approximately 3000 hours remove the check valves, clean them in solvent and blow
out the lines with compressed air. Inspect for leaks after servicing.
Item 29 Fan Hub
If the fan-bearing hub assembly is provided with a grease fitting, use a hand grease gun and lubricate the
bearings with one shot of Texaco Premium RB grease, or an equivalent Lithium base multipurpose grease,
every 12 months or 20,000 miles (700 hours).
Every 2500 hours or 75,000 miles (vehicle engines) and 4000 hours (nonvehicle engines) clean, inspect and
repack the fan-bearing hub assembly with the above recommended grease (refer to Engine Cooling Fan).
At a major engine overhaul, remove and discard the bearings in the fan hub assembly. Pack the hub
assembly, using new bearings, with Texaco Premium RB grease, or an equivalent Lithium base multipurpose
grease.
Item 30 Thermostats and Seals
Check the thermostats and seals (preferably at the time the cooling system is prepared for winter operation).
Replace the seals if necessary.
Item 31 Blower Screen
Inspect the blower screen and gasket assembly annually (vehicle engines) or every 1000 hours or 30,000 miles
(nonvehicle engines) and, if necessary, clean the screen in fuel oil and dry it
with compressed air. Install the screen and gasket assembly with the screen side of the assembly toward the
blower. Inspect for evidence of blower seal leakage.
Item 32 Crankcase Breather
Remove the externally mounted crankcase breather assembly annually (vehicle engines) or every 1000 hours
or 30,000 miles (nonvehicle engines) and wash the steel mesh pad in clean fuel oil. This cleaning period may
be reduced or lengthened according to severity of service.
Clean the breather cap, mounted on the valve rocker cover, in clean fuel oil every time the engine oil is
changed.
Item 33 Fan
DRIVE BEARING LUBRICATION:
The fan drive bearing should be lubricated as outlined in the chart with a Medium Consistency Silicone Grease
(Dow Corning No. 44, or equivalent).
The bearing on current fan assemblies is lubricated through a grease fitting in the drive housing hub.
Lubrication
Figure 11. Item 31
