Power Steering Gear, Sheppard M100 46.05 Automatic Relief Plunger Repair Procedure

There is a relief plunger in the cylinder head and one The spring pin, flange, and plunger body should in the bearing cap. Follow the appropriate set of pro- be accessible for repair at this point. cedures for the relief plunger you are repairing. CAUTION Repair Procedure for the Do not allow the screwdriver bit to slip off the Cylinder Head Automatic plunger body. Damage to the bore could result. Relief Plunger NOTE: The relief plunger flange is held in place with patch lock and the threads are staked at 1. Turn off the engine, apply the parking brakes, the factory. It will require approximately 15 to 20 and chock the tires. lbf·in (150 to 205 N·cm) to remove the flange. 2. Open the hood or tilt the cab. For cab tilt instruc- 9. Carefully insert a screwdriver bit into the plunger tions, see Group 60 in this manual. bore to hold the slotted head of the relief plunger 3. Remove the steering driveline. For instructions, body in place. Using an open-end wrench to hold see Section 46.04, Subject 100. the flange in place, carefully turn the flange to remove the flange from the plunger body. See 4. Verify that the steering gear has automatic relief Fig. 2. Discard the flange. plungers. Steering gears with automatic relief plungers will have the word AUTO cast into the housing. See Fig. 1. Steering gears with automatic relief plungers also have plastic caps on the plunger bosses. 1 3 4

01/30/2001 f461900

Fig. 1, Automatic Relief Plunger Identiﬁer

5. Place a drain pan under the steering gear. 04/26/2001 f461891 6. Mark the cylinder head and the steering gear 1. Plunger Body 3. Spring Pin 2. Flange Nut 4. Screwdriver Bit housing for later reference during installation. Remove the capscrews that attach the cylinder Fig. 2, Remove the Flange head to the housing. Remove the cylinder head. 10. Remove the plunger body from the spring pin 7. Remove the plastic cap from the plunger boss. and discard the plunger body. It may be necessary to tap the plunger body to remove it from CAUTION the spring pin. Use of a 1/8-inch pin punch is recommended. When driving the relief plunger assembly, do not allow the 1/4-inch punch to contact the bore and IMPORTANT: Check the plunger bore for nicks do not hit the plunger with excessive force. Fail- or gouges before installing the plunger assem- ure to follow these directions could result in bly. Be careful not to introduce dirt or contami- damage to the steering gear or relief plunger as- nants in the plunger bore when reassembling. sembly. 11. Coat the O-ring on the new plunger assembly 8. Place the cylinder head in a vise. Using a 1/4- with a light coat of grease. Install the plunger inch punch and hammer, carefully drive the relief body through the spring pin. See Fig. 3. plunger assembly in until it bottoms in the bore.

Century Class Trucks Workshop Manual, Supplement 24, June 2005 150/1 46.05 Power Steering Gear, Sheppard M100 Automatic Relief Plunger Repair Procedure

01/29/2001 f461903

Fig. 3, Install the Plunger Body NOTE: The plunger body has patch lock on the 01/30/2001 f461902 threads. It will require approximately 15 to 20 1. Plunger Body 3. Cylinder Head lbf·in (150 to 205 N·cm) to overcome the patch 2. Center Punch lock. Fig. 4, Stake the Threads 12. Use a screwdriver bit and ratchet to hold the plunger body in place. Using an open-end der head capscrews. Tighten the capscrews 114 wrench, install the flange on the plunger body to 124 lbf·ft (154 to 168 N·m). until the flange contacts the spring pin. 15. Install the plastic cap on the plunger boss. WARNING 16. Install the steering driveline. For instructions, see Section 46.04, Subject 100. The flange must contact the spring pin. If it does 17. Fill the power steering reservoir with an ap- not, a leak or steering gear damage may result. proved fluid. This could cause steering failure, possibly resulting in personal injury or property damage. 18. Start the engine. Check the fluid level in the power steering reservoir and add more fluid if WARNING necessary. Check for leaks. 19. Set the automatic relief plunger. For instructions, Use extreme caution when staking the threads of see Subject 140. the plunger body. Hitting the threads too hard could bend the plunger, which could cause steer- 20. Remove the drain pan. ing failure, possibly resulting in personal injury 21. Return the hood or cab to the operating position. or property damage. For cab tilt instructions, see Group 60 in this 13. With the flange against the spring pin, use a cen- manual. ter punch to stake the threads of the plunger 22. Remove the chocks from the tires. body. See Fig. 4. Be careful not to bend the plunger when staking the threads. 14. Align the marks on the cylinder head with the marks on the steering gear housing and install the cylinder head on the housing using the cylin-

150/2 Century Class Trucks Workshop Manual, Supplement 24, June 2005 Power Steering Gear, Sheppard M100 46.05 Automatic Relief Plunger Repair Procedure

Repair Procedure for the CAUTION Bearing Cap Automatic Relief Do not allow the screwdriver bit to slip off the Plunger plunger body. Damage to the bore could result.

1. Turn off the engine, apply the parking brakes, NOTE: The relief plunger flange is held in place and chock the tires. with patch lock and the threads are staked at the factory. It will require approximately 15 to 20 2. Open the hood or tilt the cab. For cab tilt instruc- lbf·in (150 to 205 N·cm) to remove the flange. tions, see Group 60 in this manual. 11. Carefully insert a screwdriver bit into the plunger 3. Verify that the steering gear has automatic relief bore to hold the slotted head of the relief plunger plungers. Steering gears with automatic relief body in place. Using an open-end wrench to hold plungers will have the word AUTO cast into the the flange in place, carefully turn the flange to housing. See Fig. 1. Steering gears with auto- remove the flange from the plunger body. See matic relief plungers also have plastic caps on Fig. 5. Discard the flange. the plunger boss. 4. Place a drain pan under the steering gear. 5. Mark the bearing cap and steering gear housing for reassembly. 6. Disconnect the steering driveline from the steering gear input shaft. For instructions, see Sub- ject 100. 7. Remove the plastic cap from the plunger boss. CAUTION When driving the relief plunger assembly, do not allow the 1/4-inch punch to contact the bore and do not hit the plunger with excessive force. Fail- ure to follow these directions could result in damage to the steering gear or relief plunger as- 03/06/2001 f461890 sembly. Fig. 5, Remove the Flange 8. Using a 1/4-inch punch and hammer, carefully drive the relief plunger assembly in until it bot- 12. Remove the plunger body from the spring pin toms in the bore. and discard the plunger body. It may be necessary to tap the plunger body to remove it from 9. Remove the four capscrews that attach the bear- the spring pin. Use of a 1/8-inch pin punch is ing cap to the steering gear housing. recommended. IMPORTANT: Check the plunger bore for nicks CAUTION or gouges before installing the plunger assem- Do not force the input shaft when turning it out bly. Be careful not to introduce dirt or contami- of the housing. The shaft could bind and steering nants in the plunger bore when reassembling. gear damage could result. 13. Coat the O-ring on the new plunger assembly 10. Separate the bearing cap assembly from the with a light coat of grease. Install the plunger housing by turning the input shaft out of the body through the spring pin. See Fig. 6. housing. Turn the shaft until it stops.

Century Class Trucks Workshop Manual, Supplement 24, June 2005 150/3 46.05 Power Steering Gear, Sheppard M100 Automatic Relief Plunger Repair Procedure

18. Connect the steering driveline to the steering 1 gear input shaft. For instructions, see Sub- ject 100. 19. Fill the power steering reservoir with an ap- 2 proved fluid. 3 20. Start the engine. Check the fluid level in the power steering reservoir and add more fluid if necessary. Check for leaks. 04/26/2001 f461901 21. Set the automatic relief plunger. For instructions, 1. Bearing Cap 3. Spring Pin see Subject 140. 2. Plunger Body 22. Remove the drain pan. Fig. 6, Install the Plunger Body 23. Return the hood or cab to the operating position. For cab tilt instructions, see Group 60 in this WARNING manual. The flange must contact the spring pin. If it does 24. Remove the chocks from the tires. not, a leak or steering gear damage may result. This could cause steering failure, possibly resulting in personal injury or property damage. NOTE: The plunger body has patch lock on the threads. It will require approximately 15 to 20 lbf·in (150 to 205 N·cm) to overcome the patch lock. 14. Use a screwdriver bit and ratchet to hold the plunger body in place. Using an open-end wrench, install the flange on the plunger body until the flange contacts the spring pin. WARNING Use extreme caution when staking the threads of the plunger body. Hitting the threads too hard could bend the plunger, which could cause steering failure, possibly resulting in personal injury or property damage. 15. With the flange against the spring pin, use a center punch to stake the threads of the plunger body. See Fig. 4. Be careful not to bend the plunger when staking the threads. 16. Align the marks on the bearing cap with the marks on the steering gear housing and install the bearing cap on the housing using the bearing cap capscrews. Tighten the capscrews 114 to 140 lbf·ft (154 to 190 N·m). 17. Install the plastic cap on the plunger boss.

150/4 Century Class Trucks Workshop Manual, Supplement 24, June 2005