Fuel Pump Drive
The fuel pump drive assembly consists of an aluminum housing, a helical gear driven off the bull gear, a drive shaft supported in the middle by a double-row ball bearing, and a forked hub which mates with a drive coupling. The fuel pump drive is supplied as an assembly, so components are not serviced. The drive gear and hub are pressed onto the drive shaft. A rubber O-ring located in a groove machined into the mounting surface of the drive is used to seal the fuel pump assembly to the gear case. An internal-type snap ring is fitted to a groove in the fuel pump drive housing to retain the bearing and shaft.
Note: Effective with engine serial number 04R0030272 built on October 27, 1999, gear case-mounted fuel pumps have a splined drive shaft and splined gear drive assembly. See Figure "Current and Former Gear Case-Mounted Fuel Pumps" . The former and current fuel pump and drive assemblies are not interchangeable. Both current assemblies must be used together. Components of former and current pump assemblies and drive assemblies are not interchangeable.
2. Gear, Fuel Pump Drive
3. Bolt, Fuel Pump Drive Retaining (5)
8. Fuel Pump Drive Assembly
4. Spline Shaft
5. Fuel Pump Assembly
Figure 1. Current and Former Gear Case-Mounted Fuel Pumps
The coupling between the fuel pump and fuel pump drive hubs is plastic, and acts as a shock absorber in the fuel pump drive line.
Lubrication of Fuel Pump Drive Bearing
The fuel pump drive bearing is lubricated by engine oil splash-fed by the gears rotating in the gear case. This oil feeds the bearing and drive shaft through a hole in the fuel pump drive housing.
Removal of Fuel Pump Drive Assembly
Remove the fuel pump drive assembly as follows:
- Remove the bolts retaining the assembly to the gear case.
Failure to remove the fuel pump drive assembly by pulling it straight out may damage the O-ring.
- Remove the fuel pump drive assembly by pulling it straight out of the gear case.
Clean the Fuel Pump Drive Assembly
Clean the fuel pump drive assembly as follows:
- Clean the mating surfaces of the fuel pump drive assembly and gear case with fuel oil.
To avoid injury from flying debris when using compressed air, wear adequate eye protection (face shield or safety goggles) and do not exceed 276 kPa (40 psi) air pressure.
- Dry the fuel pump drive assembly with compressed air.
Inspection of Fuel Pump Drive Assembly
Perform the following to inspect the fuel pump drive assembly:
- The fuel pump drive assembly is nonserviceable if the bearing is worn or scored. Replace the fuel pump drive assembly.
Installation of Fuel Pump Drive Assembly
Perform the following steps to install the fuel pump drive assembly:
- Replace the O-ring as necessary.
- Lubricate the O-ring with a light coating of petroleum jelly.
- Install the O-ring on the fuel pump drive housing.
- Install the drive assembly on the gear case.
Note: It may be necessary to use a brass hammer or fiber mallet to seat the drive assembly. Be careful not to damage the O-ring during installation.
- Install the fuel drive bolts and torque to 30-34 N·m (22-25 lb·ft) using the torque pattern shown. See Figure
"Fuel Drive Torque Sequence"
Figure 2. Fuel Drive Torque Sequence
- Install the fuel pump. Refer to "2.5.5 Installation of Gear Train-Driven Fuel Pump" for gear train-driven fuel pump. Refer to "2.5.6 Installation of Air Compressor Driven Fuel Pump" for air compressor-driven fuel pump.
- Install any other components that were removed for this procedure.
To avoid injury before starting and running the engine, ensure the vehicle is parked on a level surface, parking brake is set, and the wheels are blocked.
Diesel engine exhaust and some of its constituents are known to the State of California to cause cancer, birth defects, and other reproductive harm.
- Always start and operate an engine in a well ventilated area.
- If operating an engine in an enclosed area, vent the exhaust to the outside.
- Do not modify or tamper with the exhaust system or emission control system.
- Start the engine and check for leaks. If leaks are found. Repair as necessary.
- Shut down the engine upon completion of inspection.
|Series 50 Service Manual - 6SE50|
|Generated on 10-13-2008|