TP-6252 2/08
41
Section 3 Scheduled Maintenance
3.10 Belt Tension
Hazardous voltage.
Can cause severe injury or death.
Operate the generator set only when
all guards and electrical enclosures
are in place.
Moving parts.
WARNING
Servicing the generator set when it is operating. Exposed
moving parts can cause severe injury or death.
Keep
hands, feet, hair, clothing, and test leads away from the belts
and pulleys when the generator set is running. Replace
guards, screens, and covers before operating the generator
set.
Check the belt tensions at the interval specified in the
service schedule. If tensions are not within the
specifications, adjust as necessary using the following
procedures.
1
11
10
9
8
7
6
5
2
3
4
TP-5586-3
1. Engine-driven water pump pulley
2. Adjusting arm pivot screw
3. Battery charging alternator pulley
4. Alternator adjusting screw
5. Alternator pivot screw
6. Check the alternator belt deflection (tension) here
7. Crankshaft pulley
8. Check the seawater pump belt deflection (tension) here
9. Seawater pump adjusting screw
10. Seawater pump pulley
11. Pivot screw
Figure 3-15
Belt Tension (Typical)
3.10.1 Seawater Pump Belt Tensioning
Procedure, If Equipped
1. Remove the belt guard.
2. Check the belt tension at the midpoint of the
longest span of the belt using a belt-tensioning tool
set to 55 ft. lbs. See Figure 3-15. Recheck a new
belt tension after 10 minutes of operation.
Note:
If the belt tension is not within specifications,
go to step 3. If the belt tension is within
specifications, go to step 7.
3. Loosen the pivot and adjusting screws.
4. While prying the seawater pump outward, tighten
the adjusting screw.
5. Tighten the pivot screw.
6. Recheck and adjust as necessary.
7. Replace the belt guard.
3.10.2 Battery Charging Alternator Belt
Tensioning Procedure
1. Remove the belt guard.
2. Check the belt tension at the midpoint of the
longest span of the belt by pressing with your
finger. See Figure 3-15 and Figure 3-16. If the belt
is not within the specifications, go to step 3. If the
belt is within the specifications, go to step 7.
Belt Type
Deflection mm (in.)
New
8--12 (0.3--0.5)
Used
10--14 (0.4--0.6)
Figure 3-16
Belt Specifications
3. Loosen the adjusting arm pivot screw, alternator
pivot screw, and alternator adjusting screw.
4. While prying the alternator outward, tighten the
alternator adjusting screw.
5. Tighten the adjusting arm pivot screw and
alternator pivot screw.
6. Recheck and adjust as necessary.
7. Replace the belt guard.