ALTERNATOR AS 5L1243 - Caterpillar

3408 Marine EnginesDescription of Change: Extended shafts are now available for front power takeoff units that do not use a pilot bearing. The new shafts are six inches (152.4 mm) longer than the standard shafts, and are for use with an "outboard" bearing. In some applications, use of an "outboard" bearing gives longer clutch service life, and the new shafts will make this type of installation easier. Formerly, it was necessary to fabricate a shaft to use with an outboard bearing. The pilot end is on the new shaft to permit bearing alignment during installation. After alignment of the power takeoff unit, remove the pilot bearing.Adaptable To: All earlier engines. The new 5N7149 Clutch Shaft can be used in place of the 5N1780 Clutch Shaft for single-plate clutches (Twin Disc Model SP111). The new 5N7150 Clutch Shaft can be used in place of the 5N1781 Clutch Shaft for double-plate clutches (Twin Disc Model SP211). A Special Instruction, Form SMHS7684, is available with information to fabricate a bearing support and for alignment of the bearing and shaft.