Series 50 – Section 1.27 Crankshaft Timing Gear and Timing Wheel

Section 1.27
Crankshaft Timing Gear and Timing Wheel

The crankshaft timing gear is a helical gear that is indexed to the crankshaft by a key and is pressed onto the end of the crankshaft. See Figure "Crankshaft Timing Gear and Related Parts" .‪

The Series 50 Engine crankshaft timing gear can be identified by a groove on the outside of the gear face. ‪

Figure 1. Crankshaft Timing Gear and Related Parts

The crankshaft timing gear directly drives the bull gear and oil pump drive gear. The bull gear drives the various accessories, and drives the camshaft through the idler gear. See Figure "Engine Gear Train" .‪

Figure 2. Engine Gear Train

A timing wheel is installed on the crankshaft directly behind the crankshaft timing gear. The timing wheel is indexed to the crankshaft by the same key as the crankshaft timing gear, and is retained to the crankshaft by the crankshaft timing gear. The timing wheel is marked with the word OUT on the outboard side, and should be installed with this mark facing you as you install the wheel. See Figure "Crankshaft Timing Gear and Related Parts Location" .‪

Figure 3. Crankshaft Timing Gear and Related Parts Location

The timing wheel induces a voltage signal in the Timing Reference Sensor (TRS), as the teeth of the pulse wheel passes by the TRS. This signal is sent to the Electronic Control Module (ECM) as each cylinder reaches 10° before top-dead-center.‪

Since the crankshaft and camshaft must be in time with each other, a series of timing marks are stamped or etched on the faces of the gears in the gear train. Refer to "1.21.2.1 Check Engine Timing" for gear train timing information. The balance shafts and crankshaft must also be in time with each other. ‪

The crankshaft timing gear is lubricated by splash from the engine oil pan, and excess oil returning to the oil pan from the other gears.‪

Section 1.27.1
Repair or Replacement of Crankshaft Timing Gear and Timing Wheel

To determine if repair or replacement of the crankshaft timing gear and timing wheel are necessary, perform the following procedure. See Figure "Flowchart for Repair or Replacement of Crankshaft Timing Gear and Timing Wheel" .‪

Figure 4. Flowchart for Repair or Replacement of Crankshaft Timing Gear and Timing Wheel

Section 1.27.2
Removal of Crankshaft Timing Gear and Timing Wheel Removal

Remove the gear and the timing wheel as follows:‪

1. Drain the cooling system. Refer to "13.5.4 Cooling System" .
2. Remove the radiator to engine coolant hoses.
3. Remove the timing reference sensor. Refer to "2.21.2 Removal of Timing Reference Sensor" .
4. Remove components as necessary to gain access to the gear case cover.
5. Remove the gear case cover. Refer to "1.10.2 Removal of Gear Case Cover" .
6. If an oversize crankshaft front oil seal sleeve is used, peen the outside diameter of the sleeve until it stretches sufficiently and slip the sleeve off of the crankshaft. Discard sleeve.
7. Remove the balance assembly. Refer to "1.28.2 Cleaning and Removal of the Balance Shaft and Oil Pump Mechanism" .

   NOTICE:
   Use care when removing the bull gear assembly. To prevent damaging the crankshaft oil seal contact surface, use Crankshaft Protector, J 35994 on end of crankshaft or oil leaks may result.‪

8. Remove the bull gear and camshaft idler gear assembly. Refer to "1.26.2 Removal of Bull Gear and Camshaft Idler Gear Assembly" .
9. Using two of the crankshaft pulley bolts, secure the base post, J 35642-1 part of J 35642 , part of tool kit J 35642 , to the end of the crankshaft. Torque the bolts to 190-203 N·m (140-150 lb·ft). See Figure "Installation of Crankshaft Timing Gear Removal Tools" .
   

   Figure 5. Installation of Crankshaft Timing Gear Removal Tools

   Note: The crankshaft removal values are shown with the crankshaft installed in the engine. The crankshaft timing gear may be removed with the crankshaft in or out of the engine.

10. Thread the three legs, J 35642-2 part of J 35642 , part of tool kit J 35642 , into the three threaded holes in the crankshaft timing gear. Tighten the legs so they are snug.
11. Slide the hydraulic ram of portable press, J 35951-175 , over the center rod of base post, J 35642-1 part of J 35642 part of tool kit J 35642 , and all the way to the base. See Figure "Hydraulic Ram Installation" .
    

    Figure 6. Hydraulic Ram Installation

12. Install the Pressure Plate, J 35642-4 part of J 35642 , to the three legs, J 35642-2 part of J 35642 , both part of tool kit J 35642 . See Figure "Pressure Plate Installation" .
    

    Figure 7. Pressure Plate Installation

13. Install the three retaining nuts to the legs. Tighten the nuts to the pressure plate. Tighten the nuts until they are snug. See Figure "Retaining Nuts Installation" .
    

    Figure 8. Retaining Nuts Installation

14. Close the valve on the hydraulic pump of portable press J 35951-175 . Pump the lever to build pressure and remove the crankshaft timing gear. See Figure "Crankshaft Timing Gear Removal" .

    Note: Considerable pressure is required to remove the crankshaft timing gear. Due to manufacturer's tolerances, it may take as much as 80 kN (9 tons) of force to remove the crankshaft timing gear.

    

    Figure 9. Crankshaft Timing Gear Removal

15. Remove the tools from the engine and timing gear as follows:
    1. Open the valve on the hydraulic pump of portable press, J 35951-175 , to relieve the pressure.
    2. Loosen and remove the three retaining nuts on the legs, J 35642-2 part of J 35642 , part of tool kit J 35642 , against the pressure plate.
    3. Remove the pressure plate, J 35642-2 part of J 35642 , part of tool kit J 35642 .
    4. Remove the hydraulic ram of portable press, J 35951-175 .
    5. Loosen and remove the three legs, J 35642-2 part of J 35642 , part of tool kit J 35642 .
    6. Loosen and remove the two crankshaft pulley bolts and remove the base post, J 35642-1 part of J 35642 , part of tool kit J 35642 .

    NOTICE:
    Care should be exercised when removing the timing wheel. Do NOT use sharp tools to pry on the timing wheel. Damage to the crankshaft seal contact surface may cause oil leaks.‪

16. Slide the timing wheel off the end of the crankshaft.

    Note: The timing wheel is a slip fit to the crankshaft, and no special tools are required for removal. A three-jaw adjustable puller, however, may be necessary.

Section 1.27.2.1
Inspection of Crankshaft Timing Gear and Timing Wheel

Inspect the crankshaft timing gear and timing wheel as follows:‪

1. Clean the crankshaft timing gear and timing wheel with clean fuel oil.

   EYE INJURY ‪
   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.‪

2. Dry all parts with compressed air.
3. Examine the gear teeth of the crankshaft timing gear for evidence of scoring, pitting, or excess wear.
4. If gear teeth are damaged or worn, install a new gear.

   Note: If gear teeth are damaged or severely worn, also check the other gears in the gear train. Refer to "1.21 Gear Train and Engine Timing" .

5. Examine the timing wheel for evidence of pitting and the gear teeth for bending or damage.
6. If wheel is pitted or gear teeth damaged, replace timing wheel.

Section 1.27.3
Installation of Crankshaft Timing Gear and Timing Wheel

Install the crankshaft timing gear and timing wheel as follows:‪

1. Install the base post, J 35642-1 part of J 35642 , part of tool kit J 35642 , to the end of the crankshaft, using two crankshaft pulley retaining bolts. Torque the bolts to 190-203 N·m (140-150 lb·ft). See Figure "Base Post Installation" .
   

   Figure 10. Base Post Installation

2. If removed, install the key to the keyway. Tap the key with a plastic mallet or brass hammer to seat. See Figure "Non-Lock Key Installation" .
   

   Figure 11. Non-Lock Key Installation

3. Index the keyway of the timing wheel with the key in the crankshaft. Slide the timing wheel onto the crankshaft, with the word OUT on the timing wheel facing you, as far as it will go without forcing it. See Figure "Timing Wheel Installation" .
   

   Figure 12. Timing Wheel Installation

4. Coat the bore of the crankshaft timing gear with a film of Lubriplate.
5. Index the keyway of the crankshaft timing gear with the Woodruff key in the crankshaft. Tap the gear with a plastic hammer or fiber mallet, to ensure that the key is started in the keyway. See Figure "Crankshaft Timing Gear Indexing" .
   

   Figure 13. Crankshaft Timing Gear Indexing

6. Install the three legs of timing gear puller, J 35642-2 part of J 35642 , part of tool kit J 35642 , to the threaded holes in the crankshaft timing gear. Tighten the three legs, but do not torque. See Figure "Puller Leg Installation" .
   

   Figure 14. Puller Leg Installation

7. Install the pressure plate, J 35642-4 part of J 35642 , part of tool kit J 35642 , to the three pulley legs. Seat the pressure plate against the flanges on the puller legs. See Figure "Pressure Plate Installation" .
   

   Figure 15. Pressure Plate Installation

8. Install the three retaining nuts to the puller legs. Thread the nuts past the first set of threads on the legs. Slide the nuts past the unthreaded portion of the shafts, and engage the second set of threads. Tighten but do not torque the retaining nuts. See Figure "Crankshaft Timing Gear Installation Tools" .
   

   Figure 16. Crankshaft Timing Gear Installation Tools

9. Install the hydraulic ram to the base post rod. See Figure "Crankshaft Timing Gear Installation Tools" .
10. Install the stop nut, J 35642-3 part of J 35642 , part of tool kit J 35642 , to the end of the base post threaded rod. Tighten the stop nut.
11. Close the valve on the hydraulic pump, J 35951-175 . Work the pump handle to supply hydraulic pressure to the ram. Make sure that the slot in the crankshaft timing gear indexes with the key in the crank. Pump until the crankshaft timing gear is seated firmly against the timing wheel and the timing wheel is seated firmly against the crankshaft flange. See Figure "Crankshaft Timing Gear Installation" .

    Note: A minimum force of 30 kN (3.37 tons) must be obtained when pressing the gear on the crankshaft.

    

    Figure 17. Crankshaft Timing Gear Installation

12. Remove the special tools as follows:
    1. Open the valve on the hydraulic pump.
    2. Remove the stop nut, J 35642-3 part of J 35642 , part of tool kit J 35642 , from the end of the base post threaded rod.
    3. Remove the hydraulic ram from the base post rod.
    4. Remove the three retaining nuts from the puller legs of timing gear puller, J 35642-2 part of J 35642 , part of tool kit J 35642 .
    5. Remove the pressure plate, J 35642-4 part of J 35642 , part of tool kit J 35642 , from the three pulley legs.
    6. Remove the three legs of timing gear puller, J 35642-2 part of J 35642 , part of tool kit J 35642 , from the threaded holes in the crankshaft timing gear.
    7. Remove the base post, J 35642-1 part of J 35642 , part of tool kit J 35642 , and two crankshaft pulley retaining bolts from the end of the crankshaft.
13. Install the bull gear and camshaft idler gear assembly to the gear case. Refer to "1.26.3 Installation of Bull Gear and Camshaft Idler Gear Assembly" .

    Note: Be sure to time the gears as instructed.

14. Install the balance assembly and outlet pipes. Refer to "1.28.3 Installation of the Balance Shaft" .
15. Measure the gear lash between the crankshaft timing gear and oil pump drive gear. Refer to "1.21.2.1 Check Engine Timing" .
16. Measure the lash between the crankshaft timing gear and the bull gear. Refer to "1.21.2.1 Check Engine Timing" .
17. Install the gear case cover. Refer to "1.10.3 Installation of Gear Case Cover" .
18. Install a new crankshaft seal and sleeve. Refer to "1.8.7 Installation of Front and Rear Crankshaft Oil Seal and Wear Sleeve" .
19. Install the timing reference sensor (TRS). Refer to "2.21.3 Installation of Timing Reference Sensor" .
20. Install any components that were removed for access to the gear case cover.