Series 50 – Section 1.29 Accessory Drive

Section 1.29
Accessory Drive

The accessory drive assembly is mounted to the front of the gear case cover and utilizes a two-groove pulley to drive the alternator. See Figure "Accessory Drive Assembly Related Parts" .‪

1. Locknut‪	8. Drive Gear‪
2. Mounting Bolts (5)‪	9. O-ring‪
3. Drive Housing‪	10. Gear Case Cover‪
4. Snap Ring (Small)‪	11. Needle Bearing‪
5. Ball Bearing‪	12. Oil Seal‪
6. Snap Ring (Large)‪	13. Pulley‪
7. Driveshaft‪	‪

Figure 1. Accessory Drive Assembly Related Parts

The accessory drive assembly is splash fed oil through two holes in the casting of the accessory drive housing. The oil returns to the crankcase via the gear case.‪

The accessory drive is driven by a drive gear which is pressed onto the driveshaft. The drive gear meshes with the bull gear and is driven at 2.41 times engine speed.‪

The driveshaft is supported by a ball bearing at the drive end and a needle bearing at the pulley end.‪

Note: A design change has been made to the accessory drive assembly. The needle bearing inner race is now incorporated into the driveshaft. See Figure "Accessory Drive Assembly Related Parts" .

An O-ring is used to seal the accessory drive housing to the gear case cover.‪

Section 1.29.1
Repair and Replacement of the Accessory Drive

To determine if repair is possible or replacement is necessary, perform the following procedures. See Figure "Flowchart for Repair or Replacement of Accessory Drive" .‪

Figure 2. Flowchart for Repair or Replacement of Accessory Drive

Section 1.29.2
Cleaning and Removal of the Accessory Drive

Precleaning is not necessary.‪

Remove the accessory drive as follows:‪

1. Loosen the alternator mounting bolts and the adjusting rod nuts to get slack in the alternator drive belts. Remove the alternator drive belts. See Figure "Alternator Mounting Bolts" .
   

   Figure 3. Alternator Mounting Bolts

2. Loosen and remove the five bolts that secure the accessory drive assembly to the gear case cover.
3. Remove the accessory drive assembly by pulling it straight out of the gear case cover to avoid damaging the rubber O-ring. See Figure "Accessory Drive Assembly Removal" .
   

   Figure 4. Accessory Drive Assembly Removal

Section 1.29.3
Disassembly of the Accessory Drive

Disassemble the accessory drive as follows:‪

Note: For disassembly and assembly of the accessory drive use toolset J 36024-D. See Figure "Accessory Drive Service Tool Set J 36024-D"

Note: Engines built after December 2000, use the following tools for accessory drive seal removal and installation: J 45533 seal remover, J 45833 seal installer, and J 45877 seal runout gauge adapter to verify proper installation of seal in accessory drive. These tools are part of toolset J 36024-D. See Figure "Accessory Drive Service Tool Set J 36024-D" .

Note: The seal, pulley and pulley nut are the only serviceable parts of the accessory drive assembly with the unitized oil seal.

Figure 5. Accessory Drive Service Tool Set J 36024-D

1. Attach the accessory drive gear to the holding fixture, J 36024-3 part of J 36024–C , using the three bolts provided. See Figure "Holding Fixture " .
   

   Figure 6. Holding Fixture

2. Place the accessory drive assembly holding fixture into a vise. See Figure "Accessory Drive Pulley Locknut Removal" .
   

   Figure 7. Accessory Drive Pulley Locknut Removal

3. Loosen and remove the accessory drive pulley locknut.
4. Remove the accessory drive pulley by tapping it with a rubber hammer or fiber mallet. If the pulley does not come off easily, use a puller to remove it. See Figure "Accessory Drive Pulley Locknut Removal" .
   

   1. Seal Sleeve‪

   Figure 8. J 45533 Accessory Drive Seal Remover

   Note: Perform steps 5, 6, and 7 unitzed seal removal procedure, for accessory drive assemblies on engines built after December 2000.

5. Using J 45533 (part of toolset J 36024-D ), remove seal sleeve.
   1. Ensure taper end of puller bolt is pointed toward inside jaws. See Figure "J 45533 Accessory Drive Seal Remover" .
   2. Place inside jaws of tool over sleeve. See Figure "J 45533 Accessory Drive Seal Remover" .
   3. Finger tighten hex bolt on side of tool.
   4. Remove sleeve by tightening puller bolt.
6. Removal of seal.
   1. Invert puller bolt. See Figure "J 45533 Invert Puller Bolt"
      

      Figure 9. J 45533 Invert Puller Bolt

   2. Loosen hex bolt on side of tool.
   3. Using a rubber mallet, gently drive outside jaws between seal and shaft through the rubber membrane of seal until tool bottoms out.
   4. Finger tighten hex bolt on side of tool.
   5. Remove seal by tightening puller bolt.
7. Clean accessory drive housing at seal location.
8. Position the accessory drive assembly on a press bed with the holding fixture supported. See Figure "Accessory Drive Gear Removal" .
   

   Figure 10. Accessory Drive Gear Removal

9. Using a press, apply pressure through the access hole in the holding fixture, J 36024-3 part of J 36024–C , and press the driveshaft out of the gear.
10. Remove the snap ring from the accessory drive housing. See Figure "Snap Ring Removal" .
    

    Figure 11. Snap Ring Removal

11. Turn the housing over and support the accessory drive housing on the machined surface using Vee-blocks.
12. Using a press, apply pressure to the pulley end of the shaft and remove the shaft and bearing assembly.
13. Turn the accessory drive housing over, and support it on the attaching bolt bosses using Vee-blocks.

    NOTICE:
    For assemblies with inner race for needle bearing, place the accessory driveshaft in a vise with soft jaws taking care not to damage the shaft surface.‪

14. Install needle bearing remover and installer, J 36024-2 part of J 36024–C . See Figure "Needle Bearing Removal" . Apply pressure to J 36024-2 part of J 36024–C , and remove the needle bearing.
    

    Figure 12. Needle Bearing Removal

15. Apply pressure to J 36024-2 part of J 36024–C and remove the needle bearing.
16. Remove the snap ring from the accessory driveshaft. See Figure "Snap Ring Removal" .
    

    Figure 13. Snap Ring Removal

17. Position two steel press plates under the ball bearing outer race. See Figure "Ball Bearing Removal" .
    

    Figure 14. Ball Bearing Removal

    Note: Whenever the needle or ball bearing is removed from the shaft, they MUST be replaced with new bearing assemblies.

18. Use a press to apply pressure to the top of the shaft and remove the ball bearing from the shaft.

Section 1.29.3.1
Inspection of the Accessory Drive

Clean the accessory drive prior to inspection as follows:‪

1. Clean all of the parts 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 parts with compressed air.

Inspect the accessory drive as follows:‪

1. Inspect the driveshaft for damage.
   1. Check the driveshaft for galling, pitting, cracks, or other damage.
   2. If any damage is detected, replace with a new part.

Section 1.29.4
Assembly of the Accessory Drive

Assemble the accessory drive as follows:‪

1. Place a new ball bearing on the accessory driveshaft. Use tool J 36024-1A part of J 36024–C and a press to install the bearing onto the shaft until it bottoms out against the shoulder of the driveshaft. See Figure "Bearing Installation" .
   

   Figure 15. Bearing Installation

2. Install the snap ring to the accessory driveshaft making sure it is fully seated in the groove a full 360°. See Figure "Snap Ring Installation" .
   

   Figure 16. Snap Ring Installation

3. Place the needle bearing inner race on the accessory driveshaft. Use tool J 36024-1 part of J 36024–C and a press to install the bearing inner race to the shaft until it is tight against the shoulder. See Figure "Bearing Inner Race Installation" .

   Note: On current design accessory driveshaft, the needle bearing inner race is incorporated into the shaft.

   

   Figure 17. Bearing Inner Race Installation

4. Install the needle bearing to the accessory drive housing using tool J 36024-2 part of J 36024–C and a press. See Figure "Needle Bearing Installation" .
   

   Figure 18. Needle Bearing Installation

   Note: The end of the bearing with the identification numbers must be against the installer.

   Note: The word INSTALL and an arrow are etched into the tool, J 36024-2 part of J 36024–C , to facilitate correct bearing installation.

5. Lubricate the oil seal contact area of the accessory drive housing with a thin film of engine oil.
6. Install the accessory drive oil seal to the accessory drive housing using the seal installer, J 36024-4 part of J 36024–C , and a plastic hammer or fiber mallet. The oil seal must be installed flush to 0.25 mm (0.010 in.) below the face of the housing. See Figure "Accessory Drive Oil Seal Installation" .
   

   Figure 19. Accessory Drive Oil Seal Installation

7. Lubricate the oil seal with a thin film of engine oil.
8. Support the holding fixture, J 36024-3 part of J 36024–C on two steel plates and position the accessory drive housing into the hole in the fixture.
9. Install the driveshaft to the housing. See Figure "Accessory Driveshaft Preparation" .
   

   Figure 20. Accessory Driveshaft Preparation

10. Press the driveshaft into the housing by placing tool, J 36024-1A part of J 36024–C , on the bearing outer race.
11. Press the bearing into the housing until the bearing is seated against the shoulder of the housing. See Figure "Accessory Driveshaft Installation" .
    

    Figure 21. Accessory Driveshaft Installation

12. Install the snap ring to the accessory drive housing making sure the snap ring is fully seated in the groove a full 360°. See Figure "Snap Ring Installation" .
    

    Figure 22. Snap Ring Installation

13. Lubricate the contact surfaces of the bearing with clean engine lubricating oil.
14. A film of lubriplate must be applied to the drive gear end of the accessory driveshaft. See Figure "Drive Gear Installation Preparation" .
    

    Figure 23. Drive Gear Installation Preparation

15. Use a press to install the drive gear on the accessory driveshaft until it is flush with the driveshaft end. Make sure the three threaded holes are facing up. See Figure "Accessory Drive Gear Installation" .

    Note: Support the opposite end of the driveshaft on the press bed when pressing the gear on the shaft. A minimum press load of 17.8 kN (4000 lb) must be obtained when pressing the gear on the shaft.

    

    Figure 24. Accessory Drive Gear Installation

    Note: For accessory drive assemblies with unitized seals, effective with engines built after December 2000 perform the procedures in steps 16 and 17.

16. Install seal using J 45833 (part of toolset J 36024-D) by tightening installer nut until a positive stop is obtained. See Figure "J 45833 Accessory Drive Seal Installer" .
    

    1. Vise‪

    Figure 25. J 45833 Accessory Drive Seal Installer

17. Measure sleeve and run out using J 45877 (part of toolset J 36024-D) and a dial indicator. Total indicator deflection should not exceed 0.0762 mm (0.003 in.) for the sleeve and 0.1778 mm (0.007 in.) for the seal. If the run out is greater for either measurement, install a new seal. See Figure "J 45877 Seal Run Out Gauge Adaptor" .
    

    1. Dial Indicator‪

    2. Seal Sleeve‪

    Figure 26. J 45877 Seal Run Out Gauge Adaptor

18. Install the accessory drive pulley to the shaft.

    Note: If necessary, use tool J 36024-1A part of J 36024–C , to seat the pulley on the shaft. If pressing is necessary, the opposite (gear) end of the shaft must be supported during the pressing operation.

19. Attach the accessory drive holding fixture, J 36024-3 part of J 36024–C , to the drive gear. See Figure "Holding Fixture " .
20. Place the accessory drive assembly holding fixture into a vise.
21. Install and torque the accessory drive pulley locknut to 360-400 N·m (266-295 lb·ft). See Figure "Accessory Drive Pulley Locknut Tightening" .
    

    Figure 27. Accessory Drive Pulley Locknut Tightening

22. Support the accessory drive assembly. See Figure "Accessory Drive Gear TIR Measurement" .
    

    Figure 28. Accessory Drive Gear TIR Measurement

23. Assemble a dial indicator and magnetic base, so that the indicator stem rests on the face of the accessory drive gear just inboard of the drive gear teeth. See Figure "Accessory Drive Gear TIR Measurement" .
24. Zero the dial indicator.
25. Rotate the drive gear two full rotations. See Figure "Accessory Drive Gear TIR Measurement" . As the gear is rotated, the dial indicator needle may register both to the left and right of zero.
26. The total amount the dial indicator needle moves to the left and right of zero, added together, gives the total indicated run-out (TIR). Allowable TIR is 0.04 mm (0.0015 in.).

Section 1.29.5
Installation of the Accessory Drive

Install the accessory drive as follows:‪

1. Install the O-ring seal in the groove on the drive housing.
2. Lubricate the O-ring with petroleum jelly.
3. Install the accessory drive housing to its original position in the gear case cover.

   Note: The word "UP" is cast into the drive housing.

4. Install the bolts that secure the accessory drive housing to the gear case cover and torque to 30-38 N·m (22-28 lb·ft) using the pattern. See Figure "Accessory Drive Housing Bolt Torque Sequence" .
   

   Figure 29. Accessory Drive Housing Bolt Torque Sequence

5. Check the bull gear-to-accessory drive gear backlash. Refer to "1.21.2.1 Check Engine Timing" .
6. Adjust the alternator belts. Refer to "13.5.7 Drive Belts" . Tighten the alternator mounting bolts.
7. Install any other components removed for this procedure.