GENERATOR AR 5N8666 - Caterpillar

3500 Family Of EnginesDescription of Change: A new idler shaft with oil sealing washers under the bolts and a new thrust washer assembly are used in the front gear groups and accessory drive groups in the 3500 Family Of Engines. See illustration for a typical location of the new parts.
Location of the new parts and parts service bolts if the former shaft is reused (low speed gear group shown).The new idler shaft has no counterbored holes for the mounting bolts, and a sealing washer and a hardened washer are used under each bolt. The sealing washer reduces the possibility of oil leaking by the bolts. The new washer assembly is the same as the former washer assembly except for the removal of the oil grooves which are no longer needed.
Adaptable To: The new parts, used in certain combinations, are adaptable to earlier engines. The parts and quantity needed depend on the gear group and application. Refer to the applicable chart and footnotes. Be sure the sealing washers are under the larger, flat washers as shown.
Check the depth of the threads in the front housing at the location for the T55 Bolts (S1608 if the former shaft is reused). If the thread depth is only 14 mm (.6"), either add an additional 5M2894 Washer or increase the thread depth to 16 mm (.7").