TM 5-3895-346-14
PREVENTATIVE MAINTENANCE
ENGINE OVERHAUL
then readjust the tension. Check the belts and tighten the fan drive, pump drive, battery-charging generator, or
alternator and other accessory drive belts after 1/2 hour or 15 miles and again after 8 hours or 240 miles of
operation. Thereafter check the tension of the drive belts every 200 hours or 6000 miles and adjust, if
necessary. Too tight a belt is destructive to the bearings of the driven part, a loose belt will slip.
Replace all belts in a set when one is worn. Single belts of similar size should not be used as a substitute for a
matched belt set; premature belt wear can result because of belt length variation. All belts in a matched belt set
are within 0.032 inch of their specified center distances.
Adjust the belt tension so that a firm push with the thumb, at a point midway between the two pulleys, will
depress the belt 1/2 to 3/4 inch. If belt tension gage BT-33-73FA, or equivalent, is available, adjust the belt
tension as outlined in the chart.
NOTE
When installing or adjusting an accessory drive belt(s), be sure the bolt at the
accessory adjusting pivot point is properly tightened, as well as the bolt in the
adjusting slot.
Figure 4. Item 7
Item 9 Throttle Control
Every 200 hours or 6000 miles lubricate the limiting speed governor speed control shaft (in-line 53) through a
grease fitting located in the end of the shaft. Use an all purpose grease (No. 2 grade) at temperatures +30
F
(-1 ) and above. At temperatures below this use a No. 1 grade grease.
C
Item 10 Lubricating Oil Filter
Install new oil filter elements and gaskets at a maximum of 25,000 miles (vehicle engines) or 500 hours
(nonvehicle engines) or each time the engine oil is changed, whichever comes first. Any deviation, such
BELT TENSION CHART (lbs/belt)
Fan Drive
Alternator/Generator Drive Two
One inch
One Wide
Model
2 or 3
Single
two 3/8
belt
belt
belts
belt
inch or
inch
belts
3, 4-53
40-50
40-50
50-70
40-50
6, 8V-53
60-80
80-100
40-50
50-70
40-50
All
For 3-point or triangular drive use a tension of 90-120.
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