SERVICE CENTER AR 4466955 - Caterpillar

Inspecting the Rubber Element
Illustration 1 g00499815
Torsional set marks in the usable range
(A) New rubber element
(B) Used rubber element
(1) Outer marks
(2) Inner mark Inspect the torsional set marks. The rubber element is acceptable for use if inner mark (2) is between outer marks (1). The rubber element must not show any other evidence of stress.If the inner mark is positioned outside of the two outer marks, do not use the rubber element.Inspect the rubber element for the following evidence of stress:Cracks in the surface - If this condition is found, evaluate the selection of the coupling. Investigate the exposure of the rubber element to torsional vibration and/or misalignment. Determine if the element has been exposed to the following conditions, or to any other substance that attacks rubber: chemicals, contaminants, excessive torque, heat, lubricants, oxygen, ozone, petroleum products, ultraviolet light and vapors.Separation of the rubber from the inner metal ring - If this condition is found, evaluate the selection of the coupling. Except for ozone, investigate exposure of the rubber element to the same conditions that are listed for cracks.Distortion, cracks and tears in the lugs or teeth - If any of these conditions are found, evaluate the selection of the coupling. Investigate the exposure of the rubber element to impact and to torque that exceeds the rating of the coupling. Review the operation and maintenance records.Disconnection from the driving device that is caused by complete separation of the outer portion (housing) from the inner portion (hub) - If this condition is found, investigate the exposure of the rubber element to impact and to torque that exceeds the rating of the coupling. Review the operation and maintenance records. Look for instability in the operation such as governor “hunting”.Inspect the Metal Components
Inspect the metal components for cracks, porosity, and other signs of stress. Look for discoloration from the following sources. Replace any components that exhibit any of these characteristics:
Exposure to a corrosive atmosphere
Exposure to excessive heat
Evidence of chemical damageInspect the bolt holes. An oval shaped bolt hole indicates that the component has been moving against a bolt. This can be caused by the following conditions:
Improper tightening of bolts
Incorrect assembly of components
Parts with a loose fit
VibrationsReplace any component with bolt holes that are not round.Replace bolts and/or nuts that exhibit any of these characteristics: bent, worn, stripped threads and any other sign of stress.