SFN-20231230C Replace the suspension

TICO Document #: SFN-20231230C (formerly TES 249)

Description of Procedure: Remove existing front suspension spring hangers, reweld new spring hangers, and install new tapered leaf spring suspension.

Units Affected: 8579

Parts Required: KIT - TAPERED LEAF SPRINGS, 3.5" WIDE RUBBER BUSHINGS, VOLVO EV PROTOTYPE: 970063 (QTY)

Planned Labor: 3 hour

Instructions:

1. Park the vehicle on a flat surface, apply the parking brake and chock wheels. If your company utilizes a “Lock Out, Tag Out” policy, you should employ it during this procedure.

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2. First, separate the steering gear and front axle assembly by detaching the draglink.

3. To detach the draglink, remove the two 7/8” castle nuts and set aside for reinstallation (Figures 5 & 6).

4. Remove the steering gear and its associated 7/8” hardware from the chassis (Figure 5). Set aside hardware for reinstallation.

5. Find the Bendix air dryer on the right-hand side chassis frame rail.

6. Disconnect all air lines routing to the air dryer (Figures 7 & 8).

7. Remove the air dryer and it’s associated 3/8” hardware from the chassis (Figures 7 & 8). Set aside hardware for reinstallation.

8. Remove the 1” hardware from existing front and rear spring hangers (See Figures 9 & 10). Discard hardware.

9. Remove the front axle assembly from the chassis.

10. Position the chassis in a suitable manner for welding rework.

    10A If possible, position the chassis upside down for weldment rework.

11. Using a cutting wheel, cut each weld seam connecting the spring hanger block to the gusset. (Figure 11)

12. Remove and discard the gusset seen in Figure 11.

13. Using a cutting wheel, cut each weld seam connecting the spring hanger block to the bottom flange of the frame rail (Figures 11 & 12).

    • CAUTION: DO NOT COMPROMISE THE INTEGRITY OF THE FRAME RAIL BY CUTTING INTO THE BOTTOM FLANGE.

14. Remove the spring hanger block and discard.

15. Grind smooth any leftover weld slag and prepare the surface for the rewelding process.

16. Repeat these steps for both sides of the chassis.

17. Locate the steering gear mount found on the front of the left-hand side frame rail.

18. Using a cutting wheel, cut each weld seam connecting the steering gear mount to the frame (Figure 13).

19. Remove the steering gear mount from the chassis and discard.

20. Grind smooth any leftover weld slag and prepare the surface for the rewelding process.

21. Begin removing the front spring hanger weldments by cutting any weld seams that attach the weldment to the chassis. (See Figure 14 & 15)

    CAUTION: DO NOT COMPROMISE THE INTEGRITY OF THE FRAME RAIL BY CUTTING INTO THE BOTTOM FLANGE.

22. Remove the front spring hanger weldments and discard them.

23. Grind smooth any leftover weld slag and prepare the surface for the rewelding process.

24. Repeat these steps for both sides of the chassis.

25. The recommended welding wire for this procedure is 0.045” diameter (1.1 mm) Lincoln Metalshield MC-6 (90% Argon/10% CO2).

26. See Metalshield Catalog for typical operating procedures (wire feed speed, voltage, current, etc.) (Figure 16).

27. Position the new front spring hanger weldments flush with the bottom flange of the frame rail (Figure 18).

28. Locate the spring hanger mounting hole centers 149-19/32” (in horizontal direction) from the front face of the rear axle beam (Figures 17 & 18).

29. Next, ensure the centerlines of both front spring hanger weldments are 36” apart and are centered about the centerline of the chassis. (Figure 21).

    • NOTICE: Ensure the spring hanger mounting holes are concentric and are perpendicular to the chassis frame rail.

30. Apply a ¼” fillet weld between all flush surfaces of the front spring hangers and the chassis.

31. Ensure the ¼” weld seam is continuous around the entire spring hanger weldment (Figures 19 & 20).

32. Position the new steering gear mount (provided in kit) on the right hand side frame rail, flush to the front closing cross-member (Figure 22).

33. Locate the top edge of the steering gear mount 5” from the top edge of the frame rail.

    • NOTICE: Ensure the steering gear weldment mounting holes are concentric to the clearance holes on the chassis.

34. Apply a ¼” fillet weld to the two vertical edges of the steering gear mounting weldment (Figure 22).

35. Next, position the new rear spring hanger blocks flush with the bottom flange of the frame rail (Figure 23).

36. Ensure the outside faces of both spring hanger blocks are 39-1/2” apart and are centered about the centerline of the chassis (Figure 24).

37. Next, position the centerline of the rear spring hanger block 46-15/16” (in a horizontal direction) apart from the mounting hole on the front spring hanger weldments (Figure 25).

    • NOTICE: Ensure both spring hanger blocks are concentric and are perpendicular to the frame rail.

38. Apply a ¼” fillet weld between all flush surfaces of the rear spring hanger blocks and the frame.

39. Ensure the ¼” weld seam is continuous around the entire spring hanger block (Figures 26 & 27).

40. Repeat these steps for both sides of the chassis.

41. Finally, position the new gusset (provided in kit) between the top face of the spring hanger block and the inside face of the frame rails.

42. Confirm the gusset is 1-1/2” from the front face of the block and ¼” from the inside face of the block (Figures 28 & 29).

43. Apply a bevel weld to both sides of the gusset (Figure 28).

44. Repeat these steps for both sides of the chassis.

45. After all welding procedures have been completed, paint the newly welded components and surrounding areas on the chassis “TICO Black”, which is RAL #9005.

    • 45A Be sure to keep the inside faces of both rear spring hanger blocks free of paint (Figure 30).

46. With the front axle/suspension assembly removed from the chassis, begin replacing the leaf spring assemblies.

47. Remove the current leaf spring assemblies by removing the four ¾” thread U-bolts (See Figures 33 & 34). Discard these U-bolts and associated hardware (new U-bolts are provided in kit).

48. Confirming the spacer plate is underneath the left-hand side spring assembly (Figure 35), begin installing the new tapered spring assemblies.

49. Position the spring assemblies with the full box wrap eye facing rearward.

50. Install the four new U-bolts as shown in Figure 35.

51. Using a torque wrench, apply 360 ft-lb (488 N-m) of torque to all new U-bolts.

52. Next, install the new rubber bushings (P/N 123493-3, found in kit) to the rear spring hanger blocks.

53. Apply a generous amount of copper anti-seize/lubricating compound to the outside surface of the rubber bushing.

54. Press the rubber bushing into the rear spring hanger block, making sure that the bushing is centered inside of the block.

55. Install the new shackle bars (P/N 123493-4, provided in kit) by using the new ¾”-16 hardware, ensuring the locknut is on the inside face of shackle bars (Figure 37).

56. Hand tighten the thin profile locknut, P/N 80365.

57. Repeat steps for both sides.

58. Begin installing the front axle/suspension assembly into the new front spring hangers. – REVISION B: Press fit (4X) of the provided bushings, P/N 850216, into each mounting hole on the new front spring hangers (Figure 42). This will create a close fit with the new ¾” hardware.

59. Center the front eyes of the tapered suspension with the mounting holes on the front spring hangers.

60. Install the ¾”-16 hardware (provided in kit) through the front spring hangers, ensuring locknut is on the inside of the frame (See Figure 39).

61. Hand tighten the thin profile locknuts, P/N 80365.

62. Next, center the rear eyes of the tapered suspension with the rear shackle bars.

63. Using the ¾”-16 hardware, install the bolts through the shackle bars and rear tapered spring leaf eyes (Figure 43).

64. Hand tighten the thin profile locknuts, P/N 80365.

65. Finally, using a proper torque wrench, apply a 300 ft-lb torque (406 N-m) to all of the previously hand tightened ¾”-16 hardware.

66. Remount the Bendix air dryer on the righthand side frame rail (use previously removed 3/8” hardware).

67. Connect all the previously removed air lines to the air dryer.

68. Lastly, remount the steering gear to the newly welded mount on the left-hand side chassis rail.

69. Use the previously set aside 7/8” hardware to mount steering gear. Torque these 7/8” locknuts to 330 ft-lbs (470 N-m).

70. Reattach the draglink using the two 7/8” castle nuts and cotter pins. (Figures 45 & 46).

71. Torque the castle nuts to 200 ft-lbs (270 Nm) and then use the cotter pin to capture the nut in place.

72. Remove “Lock Out, Tag Out” plaque.

73. Return vehicle to service.