Camshaft or Idler Gear - Magnetic Crack Inspection (1-19) Section 1 - Cylinder Block - Group 01 M11 Page 1-58 Adjust the amperage to the specified value. Gear O.D. Ampere Turns Less than 101 mm [4 inch] 4000 101 to 203 mm [4 to 8 inch] 6000 Greater than 203 mm [8 inch] 8000 NOTE: Ampere turn is an electrical current of one ampere flowing through the coil, multiplied by the number of turns in the coil. Visually inspect the gear for cracks. Definitions of Indication Open Indication - An indication is open if, when wiped clean of magnetic particle bath, it can be seen with the naked eye in a well lighted area. Many times an open indication can be felt with a fingernail.
Subsurface Indication - An indication is subsurface if, when wiped clean of magnetic particle, it cannot be seen with the naked eye in a well lighted area. Subsurface indications are often ‘‘voids’’ or ‘‘non-metallic inclusions’’ which are present in the raw material. Camshaft or Idler Gear - Limits of Accep- tance Do NOT use a camshaft gear if: There are open indications in any direction. There are any subsurface indications in the shaded area. There are subsurface indications longer than 6 mm [1/4 inch] in the non-shaded area.