PRIORITY - PARTS STOCK ACTION NEEDED - NEW GOVERNOR SPEED FILTER NEEDS TO BE INSTALLED ON CERTAIN 3606, 3608, 3612, AND 361 6 GENERATOR SET ENGINES - PI3464 - MAILED US AND CANADA, CACO, COFA, CFEL, LIMITED CFEL Caterpillar

PRIORITY - PARTS STOCK ACTION NEEDED - NEW GOVERNOR SPEED FILTER NEEDS TO BE INSTALLED ON CERTAIN 3606, 3608, 3612, AND 361 6 GENERATOR SET ENGINES - PI3464 - MAILED US AND CANADA, CACO, COFA, CFEL, LIMITED CFEL

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Caterpillar: Confidential Yellow

PRIORITY - PARTS STOCK ACTION NEEDED - NEW GOVERNOR SPEED FILTER NEEDS TO BE INSTALLED ON CERTAIN 3606, 3608, 3612, AND 361 6 GENERATOR SET ENGINES - PI3464 - MAILED US AND CANADA, CACO, COFA, CFEL, LIMITED CFEL

NOTE: The information supplied in this service letter may not be valid after the termination date of this program. Do not perform the work outlined in this Service Letter after the termination date without first contacting your Caterpillar product analyst.


U-106
A-69
AU-71
E-66
O-82.1
PRIORITY
Parts Stock Action Needed
1264  PI3464
COMPLETION DATE

Termination Date

November 30, 1990  May 31, 1991

Problem

The governor stability on certain 3606, 3608, 3612, and 3616 Generator Set
Engines can be improved by changing the filtering of the speed signal in the
governor control group. This reduces the chance of torsional coupling
failures caused by governor induced engine instability.

Affected Product

Model Identification Number
3606 8RB298-301, 312, 320, 326, 335, 340-342, 354, 357, 365
3608 6MC243, 246, 248-251, 257-260, 264, 265, 268, 269, 271, 273,
275, 280, 281, 284-286, 289-292, 295, 302, 303
3612 9RC15, 18-22, 24, 25, 30, 32, 33, 37-48, 50, 55-64, 66-72, 78,
79
3616 1PD19-22, 24-31, 33-41

Parts Needed

Review parts stocking locations and exchange stock availability from Woodward
prior to scheduling the repair. Use reworked parts stock control groups or
obtain an exchange control group from Woodward.

Action Required

***** Parts Stock *****
Remove all existing 9Y6982, 7C7824, or 7W1444 Governor Control Groups from
parts stock and return them to Woodward Governor for rework.
The governor control groups are to be reworked at a Woodward authorized
facility per the instructions in Woodward Service Bulletin 50074.
***** Affected Product *****
Remove the existing 9Y6982, 7C7824, or 7W1444 Governor Control Group from the
engine and return it to Woodward Governor for rework.
The governor control groups are to be reworked at a Woodward authorized
facility per the instructions in Woodward Service Bulletin 50074.
Reworked governor control groups are will be identified with "7.5 Htz Filter"
stamped on the housing.
Existing  New
Part No. Description Part No.
9Y6982 Governor Control Group 4P1561
7C7824 Governor Control Group 4P1570
7W1444 Governor Control Group 4P1579
NOTE: Reworked existing part nos. are identical in function to new part
nos.
When reworked or new governor control groups are received, install them on
the engine and adjust according to the following instructions.
PRE-STARTUP INSTRUCTIONS
The pre-startup pot settings recommended in the Woodward 2301A Manual may be
too responsive for some of the Affected Product. The following pot settings
should be used for pre-startup adjustment of the governor.
Gain 2 (Based on 0 to 10)
Reset 5
Compensation 0
Changes from these settings after startup should be made with caution.
AFTER STARTUP INSTRUCTIONS
After the engine is started, warm the engine and coupling by adding load.
Remove the load and check for stable operation at low and high idle. Watch
for rapid motion of the actuator lever (about 5-10 Hz).
Shut the engine down if the rapid actuator lever motion occurs. After
shutting the engine down, either decrease the gain or slightly increase the
reset. Then, repeat the above two steps.
NOTICE: Do not set the compensation pot greater than 2 (0 is preferred).
Unstable operation may cause coupling damage if the compensation is greater
than 2.
If misfire is detected, the engine should be stopped and the fuel system
checked. Misfire can be detected by using individual exhaust temperature
alarms. Set the alarms for activation of a cylinder is 50 deg.C (122 deg.F)
lower than the mean temperature of the other cylinders.

Owner Notification

Not Applicable

Service Claim Allowances

Caterpillar Dealer Suggested Customer Suggested
Parts Labor Hrs. Parts Labor Hrs. Parts Labor Hrs.
100% 8 0 0  0 0
NOTE: This is an 8-hour job.

Parts Disposition

Any parts removed (with the exception of cores used for Caterpillar
Remanufactured parts) can be rendered useless and scrapped immediately upon
completion of the repair.