GASKET-MANIFOLD 2344824 - Caterpillar

CONFIDENTIAL TIBU3337-01
TECHNICAL INFORMATION BULLETIN May 18, 2005
Engines
This Technical Information Bulletin replaces the May 18, 2001 TIB "3306/3406 Correction of "Overspeed at Start-up" complaint on standby generator set engines". Disregard the May 18, 2001 TIB.
3306 (1CZ1-Up, 85Z1-Up, 9DS1-Up, 9NR1-Up)
3406C (1DZ1-Up, 2WB1-Up, 4ZR1-Up)
Component Code(s) 1404SUBJECT: 3306/3406 Correction of "Overspeed at Start-up" complaint on standby generator set engines
PROBLEM:
3306/3406 standby generator set engines may go into overspeed during startup when equipped with dashpot governor arrangements.
DISCUSSION: This is a problem that is somewhat characteristic of the 3306 and 3406 governor, but it can be fixed. The oil drains from the dashpot when the engine is not run for extended periods of time. As the engine cranks, oil is drawn into the dashpot by the moving dashpot plunger. Oil pressure is not an issue because the dashpot plunger draws unpressurized oil from a cavity in the governor housing. If the dashpot does not fill before the engine reaches 1500 RPM, the engine could run-up to the overspeed trip limit of the control system and shutdown.
In the past, dealers have used heating blankets to keep the governor warm or simply changed to a lower viscosity oil. Dealers have also installed a 5-second timer to delay the energize-to-run solenoid from actuating. This 5-second delay provides 5 seconds of cranking time before the engine starts, which allows the dashpot time to fill.
If equipped, the 1724 actuator linkage can be moved to the shutoff lever with modifications to the linkage arrangements. The 1724 would then be able to hold the speed down when the Caterpillar governor goes unstable during startup (before there is enough oil in the dashpot). A jumper would also need to be added so that the engine goes straight to high idle upon startup. This jumper should be connected to terminals 9 and 10 on the Woodward 8290 Control. This is the easiest fix for critical standby applications.
If the unit does not have the 1724 option, add the timer (see Steps 1 ? 6). Also confirm that the dashpot check valve is not reversed (this check valve is only used on 3304 and 3306 models). This check valve allows you to draw oil into the dashpot of the governor during cranking so that the dashpot is full before the engine reaches 1500 RPM. If the needle valve is adjusted so that it is nearly closed and if the oil is cool/cold and of relatively heavy weight, the dashpot will fill slower than normal. Ensure that you are using the correct oil and that the needle valve is adjusted correctly. The needle valve should be turned clockwise all the way in and then backed out anywhere from ? to 2 full turns.
Certain emissions-certified arrangements have a Woodward 524 actuator that is used to override the Caterpillar governor via the shutoff linkage. These arrangements cannot have this problem because the actuator controls the rack.
SOLUTION:
Solutions that can be administered for non-critical standby applications:
Lockout genset. Disconnect battery power to the control panel.
Install the 3N7817 Relay Track in the EMCPII