The document discusses wheel bearings, including their types, parts, inspection, and service procedures. It describes the symptoms of defective wheel bearings, such as noise and looseness. The summary explains how to inspect non-drive wheel bearings, including cleaning and packing them with new grease before reinstallation. Special attention is paid to properly adjusting the spindle nut during reinstallation.

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9. Figure 73–3 Radial load is the vehicle weight pressing on the wheels. The thrust load occurs as the chassis components exert a side force during cornering. Continued

13. Figure 73–6 Many tapered roller bearings use a plastic cage to retain the rollers. Continued

15. Figure 73–7 Non-drive-wheel hub with inner and outer tapered roller bearings. By angling the inner and outer in opposite directions, axial (thrust) loads are supported in both directions. Continued INNER WHEEL BEARING SPINDLE OUTER WHEEL BEARING

18. Figure 73–8 Sealed bearing and hub assemblies are used on the front and rear wheels of many vehicles. Continued

19. Figure 73–9 Sealed bearing and hub assemblies are serviced as a complete unit as shown. This assembly includes the wheel speed sensor. Continued

32. Figure 73–12 Removing the grease cap with grease cap pliers. Figure 73–13 After wiggling the brake rotor slightly, the washer and outer bearing can be easily lifted out of the wheel hub. Continued

36. Figure 73–15 Wheel bearing inspection chart - Part 1 See the entire chart on Page 874 of your textbook. Continued

37. Figure 73–15 Wheel bearing inspection chart - Part 2 See the entire chart on Page 874 of your textbook. Continued

38. Figure 73–16 A wheel bearing race puller. Figure 73–17 Installing a bearing race with a driver. Continued

45. CAUTION: Clean grease off the disc brake rotors or drums after servicing the wheel bearings. Use a brake cleaner and a shop cloth. Even a slight amount of grease on the friction surfaces of the brakes can harm the friction lining and/or cause brake noise. NOTE: Loose wheel bearings can also cause the brake pedal to sink due to movement of the rotor, causing the caliper piston to move. This sinking brake pedal is usually caused by a defective master cylinder. Before replacing a master cylinder, check the wheel bearings.

48. Figure 73–23 A special puller makes the job of removing the hub bearing from the knuckle easy without damaging any component. Continued

52. Figure 73–24 A typical full-floating rear axle assembly. The axle shafts “float” in the axle housing and drive the wheels without supporting their weight. Because the axle shafts do not retain the wheel, the axle shafts can usually be removed from the vehicle while it is standing on the wheels. Most three-quarter-ton pickups, all heavy-duty truck tractors, and trailers use full- floating axles. Continued

59. Figure 73–28 The ball bearings fell out onto the ground when this axle was pulled out of the axle housing. Diagnosing the cause of the noise and vibration was easy on this vehicle. It is often necessary to remove the axle to perform a visual inspection especially if trying to diagnose driveline noises. Continued

61. Figure 73–29 (a) To remove the axle from this vehicle equipped with a retainer-plate rear axle, the brake drum was placed back onto the axle studs backward so that the drum itself can be used as a slide hammer to pull the axle out of the axle housing. (b) A couple of pulls and the rear axle is pulled out of the axle housing. (a) (b) Slide Hammer Trick - Part 2

64. Continued Continued NOTE: When removing the differential cover, rear axle lubricant will flow from between the housing and the cover. Be sure to dispose of the old rear axle lubricant in the environmentally approved way, and refill with the proper type and viscosity (thickness) of rear-end lubricant. Check the vehicle specifications for the recommended grade.

68. Figure 73–35 (a) When corrosion etches into the surface of a roller or race, the bearing should be discarded. (b) If light corrosion stains can be removed with an oil-soaked cloth, the bearing can be reused. (Courtesy SKF USA Inc.) Continued (a) (b)

69. Figure 73–36 (a) When just the end of a roller is scored, it is because of excessive preload. Discard the bearing. (b) This is a more advanced case of pitting. Under load, it will rapidly lead to spalling. (Courtesy SKF USA Inc.) Continued (a) (b)

70. Figure 73–37 (a) Always check for faint grooves in the race. This bearing should not be reused. (b) Grooves like this are often matched by grooves in the race (above). Discard the bearing. (Courtesy SKF USA Inc.) (a) (b) Continued

71. Figure 73–38 (a) Regular patterns of etching in the race are from corrosion. This bearing should be replaced. (b) Light pitting comes from contaminants being pressed into the race. Discard the bearing. (Courtesy SKF USA Inc.) Continued (a) (b)

72. Figure 73–39 (a) This bearing is worn unevenly. Notice the stripes. It should not be reused. (b) Any damage that causes low spots in the metal renders the bearing useless. (Courtesy SKF USA Inc.) Continued (a) (b)

73. Figure 73–40 (a) In this more advanced case of pitting, you can see how the race has been damaged. (b) Discoloration is a result of overheating. Even a lightly burned bearing should be replaced. (Courtesy SKF USA Inc.) Continued (a) (b)

74. Figure 73–41 (a) Pitting eventually leads to spalling, a condition where the metal falls away in large chunks. (b) In this spalled roller, the metal has actually begun to flake away from the surface. (Courtesy SKF USA Inc.) Continued Metal Fatigue Long vehicle usage, even under normal driving conditions, causes metal to fatigue & crack. The metal between the cracks can break out into small chips, slabs, or scales of metal, called spalling . (a) (b)

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