CTM207 - PowerTech™ 4.5L and 6.8LDiesel EnginesMechanical Fuel
Install Stanadyne Model DB2 and DB4 Injection Pump (without Lock Shaft
Install Stanadyne Model DB2 and DB4 Injection Pump (without Lock Shaft Timing)
RG6278-UN: Injection Pump Timing Marks
RG7630C-UN: Pump Drive Gear Retaining Nut
A - Front Plate Timing Mark
B - Pump Timing Mark
C - Pump Drive Gear Retaining Nut
Injection pump mounting flange timing mark (B) and front plate timing mark (A) presence and alignment
MUST BE verified before removing pumps from engine. When pump is reinstalled on engine, time pump by
aligning these two (external) marks. DO NOT reference internal timing marks (on pump cam ring and governor
weight retainer) for accurate pump timing.
Lubricate a new square sealing ring with clean engine oil. Install ring into groove on front face of pump mounting
flange. Slide injection pump onto mounting studs while inserting pump shaft into drive gear.
Shaft roll pin may be easily damaged if improperly assembled. Pump drive gear should not move when
initially installing pump index pin into drive gear key slot.
Check pump shaft and index pin for proper alignment with pump drive gear key slot.
Install injection pump partially onto mounting studs without engaging pump pilot hub into engine front plate.
DO NOT tighten hex nuts more than three full turns on mounting studs. Pump drive shaft index pin may
be damaged if pin is not properly aligned with drive gear key slot and nuts are tightened more than three
Install three flat washers, lock washers, and hex nuts onto pump mounting studs. Tighten nuts three turns only so that
pump will not fall off mounting studs.
The pump drive gear should begin to move forward (away from engine front plate) with the pump
when flange is approximately 3.2 mm (1/8 in.) away from engine front plate.
Install pump mounting flang