SEAL-O-RING 1565198 - Caterpillar

Engine: 3606 (S/N: 8RB1-UP) 3608 (S/N: 6MC1-UP) 3612 (S/N: 9RC1-UP; 2NZ1-UP; 9FR1-UP) 3616 (S/N: 1PD1-UP; 1FN1-UP)Introduction
The tachometer is used to monitor the rpm of the turbocharger shaft, the turbine wheel, and the compressor wheel.If the turbocharger is rotating too fast, the service life of the bearings will be reduced. Monitoring the rpm of the turbocharger can help prevent damage.A new turbocharger operates with optimum efficiency. As the turbine and the compressor become fouled and/or worn, the efficiency of the turbocharger changes. A record of the turbocharger's rpm and corresponding factors such as boost pressure can help determine the efficiency of the turbocharger.Do not perform any procedure in this Special Instruction until you read the information and you understand the information.System Operation
The basic components that are needed for operation of the tachometer are a speed sensor, a frequency transmitter, a power source, and wiring.
Illustration 1 g00779286
Block diagram of the tachometer's system (1) Speed sensor (2) Frequency transmitter (3) Power supply (4) TachometerSpeed sensor (1) is installed in the adapter of the turbocharger air inlet. The speed sensor monitors the rotation of the turbocharger's compressor wheel. The rotation is sensed as a frequency.Note: Three different speed sensors are available for use with different types of adapters. Two of the sensors monitor rotation of the compressor wheel's shaft. The third sensor monitors the rotation of the impeller vanes.The speed sensor sends a signal to frequency transmitter (2). Positive DC voltage is provided to the transmitter by power supply (3) .The transmitter converts the signal from the speed sensor into output of 4 to 20 mA. The output is sent to tachometer (4). The digital display of the tachometer indicates the rpm of the turbocharger.
Illustration 2 g00782274
Typical displayA label of "RPM X10" is on the front of the tachometer beneath the display. The label indicates that the display represents one-tenth of the actual rpm. Therefore, the displayed value must be multiplied by ten in order to determine the actual rpm. For example, a display of "2500" represents an actual rpm of 25,000.Required Parts
Table 1
Required Parts for the Turbocharger's Tachometer    
Pt. No.     Description     Qty    
141-9884     Speed Sensor (1)     1    
168-3630     Speed Sensor (2)    
164-5336     Speed Sensor (3)    
115-7954     Frequency Transmitter     1    
144-0441     Tachometer     1    
-     Shielded two-wire cable     -    
-     16 AWG wire     -    
-     1 Amp circuit breaker or fuse (4)     1    
( 1 ) The 141-9884 Speed Sensor is used for ABB turbochargers with an adapter for the inlet air that is straight.
( 2 ) The 168-3630 Speed Sensor is used for ABB turbochargers with an adapter for the inlet air that is at 90 degrees or with a silencer.
( 3 ) The 164-5336 Speed Sensor is used for all Napier turbochargers.
( 4 ) The need for a circuit breaker or a fuse depends on the instrument