Series 55 – Section 1.25 Crankshaft Timing Gear/DDEC III Pulse Wheel

Section 1.25
Crankshaft Timing Gear/DDEC III Pulse Wheel

The crankshaft timing gear is mounted on the rear of the rear of the crankshaft. The DDEC III pulse wheel is mounted over the camshaft drive gear, a dowel pin is used to align the pulse wheel to crankshaft. See Figure "Crankshaft Timing Gear/DDEC Pulse Wheel and Related Parts" .‪

1.Pulse Wheel (DDEC III)‪	4.Crankshaft‪
2.Crankshaft Timing Gear‪	5.Larger Counterweights‪
3.Small Counterweights‪	6.Front Seal Sleeve‪

Figure 1. Crankshaft Timing Gear/DDEC Pulse Wheel and Related Parts

Section 1.25.1
Repair or Replacement of Crankshaft Timing Gear/DDEC Pulse Wheel

Perform the following procedure to determine if repair is possible or replacement is necessary. See Figure "Replacement of Crankshaft Timing Gear/DDEC Pulse Wheel Flowchart" .‪

Figure 2. Replacement of Crankshaft Timing Gear/DDEC Pulse Wheel Flowchart

Section 1.25.2
Removal of Crankshaft Timing Gear/DDEC Pulse Wheel

Pre-cleaning is not necessary.‪

Remove the crankshaft timing gear/DDEC pulse wheel as follows:‪

1. Bar the engine over until the No. 1 cylinder is at TDC. Refer to "12.2 Adjustments of Valve Lash" .
2. Install flywheel lock timing tool J 41786.
3. Drain engine oil. Refer to "13.4.1 Lubricating Oil" .
4. Remove oil pan. Refer to "3.8.2 Removal of Oil Pan" .
5. Remove the flywheel. Refer to "1.12.2 Removal of Flywheel" .
6. Remove the flywheel lock timing tool.
7. Remove the flywheel housing. Refer to "1.15.2 Removal of Flywheel Housing" .
8. Remove and discard the crankshaft rear oil seal.
9. Remove DDEC III pulse wheel. See Figure "DDEC III Pulse Wheel Removal" .
   

   1.Pulse Wheel (DDEC III)‪	4.Crankshaft‪
   2.Crankshaft Timing Gear‪	5.Larger Counterweights‪
   3.Small Counterweights‪	6.Front Seal Sleeve‪

   Figure 3. DDEC III Pulse Wheel Removal

10. Remove the crankshaft timing gear.

Section 1.25.2.1
Inspection of Crankshaft Timing Gear/DDEC Pulse Wheel

Inspect the Crankshaft Timing Gear/DDEC Pulse Wheel as follows:‪

1. Inspect timing gear for signs of broken teeth, inside diameter damaged or oblong mounting holes. If damage is found replace crankshaft timing gear.
2. Inspect for damage to guide pin. If damaged replace crankshaft timing gear.
3. Inspect DDEC III pulse wheel for damage to teeth, inside diameter damage or oblong mounting bolt holes. If damage is found, replace pulse wheel.

Section 1.25.3
Installation of Crankshaft Timing Gear/DDEC Pulse Wheel

Install the Crankshaft Timing Gear/DDEC Pulse Wheel as follows:‪

1. Install crankshaft timing gear on the crankshaft, align the dowel pin on timing gear to crankshaft. See Figure "Crankshaft Timing Gear Installation" .
   

   1.Pulse Wheel (DDEC III)‪	4.Crankshaft‪
   2.Crankshaft Timing Gear‪	5.Larger Counterweights‪
   3.Small Counterweights‪	6.Front Seal Sleeve‪

   Figure 4. Crankshaft Timing Gear Installation

2. Position the DDEC III pulse wheel over the crankshaft timing gear, by aligning the dowel pin hole in the pulse wheel with dowel pin on timing gear and the word "out" facing rear of engine.
3. Install the flywheel housing. Refer to "1.15.3 Installation of Flywheel Housing" .
4. Install rear oil seal. Refer to "1.8.7 Installation of Rear Crankshaft Oil Seal" .
5. Install the oil pan. Refer to "3.8.3 Installation of Oil Pan" .
6. Refill with engine oil. Refer to "13.4.1 Lubricating Oil" .
7. Install the flywheel. Refer to "1.12.3 Installation of Flywheel" .