OVERHAULING WORM & ROLLER STEERING GEARBOX

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AIM:

OVERHAULING OF WORM & ROLLER TYPE STEERING GEAR BOX.

TOOLS REQUIRED

1. BOX SPANNER SET
2. DOUBLE END OPEN SPANNER SET
3. DOUBLE END RING SPANNER SET
4. SCREWDRIVER (-)
5. PLASTIC HAMMER
6. TORQUE WRENCH


MATERIALS REQUIRED

1. KEROSENE OIL
2. COTTON WASTE
3. EMERY PAPER
4. TRAY
5. LUBRICATING OIL


PROCEDURE


DISMANTLING 

1. Disconnect the battery.

2. Chock the wheels.

3. Remove the bottom shield of the steering assembly.

4. Disconnect the horn button and horn wire at the bottom of steering assembly.

5. Remove the horn button.

6. Release the steering wheel nut lock.

7. Remove the steering nut.

8. Remove the steering wheel by using the puller

9. Remove the instrument panel bracket.

10. Remove the exhaust pipe from the manifold.

11. Remove the steering column cover plate on the floor board.

12. Note the position of the steering gearbox and make a mark on the frame and steering gearbox.

13. Remove the steering gearbox mounting bolts and bracket.

14. Remove the steering gearbox and take it out through the bottom side.

15. Place the steering assembly on the workbench.

16. Drain the steering gearbox oil by removing the drain plug.

17. Remove the oil filter plug.

18. Loosen the lock nut  of the adjusting screw by one or two threads.

19. Remove the side cover and packing.

20. Remove the roller shaft from the assembly.

21. Remove the outer column upper cover with the shims.

22. Remove the upper side bearing from the housing.

23. Remove the bottom end cover with the shims and packing.

24. Remove the lower bearing from the housing.

25. Remove the horn wire tube.

26. Remove the ( inner column) worm gear shaft assembly.

27. Remove the side oil seal.

CLEANING AND INSPECTION 

1. Clean all the parts with kerosene oil.

2. Inspect visually the following parts.

  ♦️Bearings for pitting and overheating.

  ♦️Rocker shaft and inner column for pitting/wear.

  ♦️Steering housing for crack and enlargement of mounting holes.

3. Replace the defective parts.

➡️ Check for bend of the inner column with the help of 'V' blocks and a dial indicator. Replace the inner column if the bend is found to be more than the specified limit recommended by the manufacturer.

ASSEMBLING

1. Check the bush for its free movement on the roller shaft.

2. Fix the bush on the side cover of the steering gearbox.

3. Fix the bush on the steering gearbox body.

4. Check the free movement of the rocker shaft in the bush by rotating the rocker shaft by hand.

5. Fix a new ball bearing at the bottom of the housing.

6. Refit the worm gear shaft inner column in the housing.

7. Fit the horn wire tube.

8. Fix the upper ball bearing in the housing.

9. Fix the top housing cap with the shims.

10. Tighten the top housing cap screws at the specified torque. Check the pre-load of the inner column. To increase the pre-load reduce the thickness of shims.

11. Insert the rocker shaft in the housing.

12. Place the side cover and side cover gasket.

13. Tighten the side cover screws at the specified torque.

14. Fix the lower ball bearing in the housing.

15. Place the bottom cover gasket and shims.

16. Place the bottom cover and tighten the bottom cover screws.

17. Fix the adjusting screw.

18. Adjust the pre-load of the roller shaft by loosening or tightening the adjusting screw as per the manufacturer's recommendation. Tightening the adjusting screw will increase the pre-load. Lock the adjusting screw after adjusting the pre-load.

19. Fix the outer column on the steering housing.

20. Insert the steering assembly from the bottom side of the vehicle.

21. Align the steering assembly position with the frame and tighten the mounting bolts at the specified torque.

22. Place the oil seal in between the steering housing and drop arm.

23. Align the drop arm and rocker shaft and fix the drop arm on the rocker shaft. Tighten the drop arm's nut and lock it by a split pin.

24. Refix the steering column cover plate on the floor board.

25. Refix the instrument panel board bracket.

26. Press the steering wheel by hitting lightly with a plastic mallet.

27. Tighten the steering wheel nut with a washer at the specified torque.

28. Lock the steering wheel nut by folding the washer.

29. Insert the horn button and wire.

30. Lock the horn button and Connect the horn wire.

31. Refill the oil as per the manufacturer's specification.

32. Refit the exhaust pipe with new packing. Then fix the bottom shield cover of the steering assembly.

RESULT:
 
Overhauling of worm and roller type steering gearbox done successfully.

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