LAMP GP-DOME 3E6389 - Caterpillar

3408, 3412 Marine EnginesDescription of Change: New clutch groups are used in front power take-offs for the above model engines. The new clutch groups use shafts that have a shorter pilot end. This lowers stresses in the shaft under heavy side loads, so the shaft has a higher side load capacity. The shorter end also changes the location of the pilot bearing so it is the same as SAE standards. In comparison with some earlier shafts, the new shaft is hardened in the area of contact with the sliding sleeve to prevent fretting (wear). In the clutch, radial springs are now used on the sliding sleeve and the adjusting ring. The pressure plates have both radial and axial springs, and spring washers are now used to keep a preload on all cotter pins. These improvements prevent much of the movement of clutch components in relation to each other. This gives lower wear rates and longer service life. Clutch service kits are now available for service repair. Each kit is a complete assembly of all the rotation parts except the shaft, and can be installed as a unit. This permits fast, easy replacement of most parts which normally wear, with much less time and labor than separate parts and generally at a lower cost. The service kit plus the new shaft can also be used for conversion of a former clutch group to the new group. Any time service work is done on a power take-off that has one of the former shafts, install the new shaft in addition to the service kit for maximum clutch service life.
Adaptable As: Direct replacement. The recommendation is to use the new service kits only with the new shafts. INSTALLATION: With the new clutch shaft, the pilot bearing location is changed. During assembly, install the pilot bearing to a dimension of 3.94" (100.1 mm) measured from the rear face (engine side) of the bearing to the mounting surface of the power take-off housing. When correctly installed, the bearing extends .10" (2.5 mm) beyond the end of the shaft. If the bearing is pressed (pushed with a press) too far on the shaft, the bearing will be damaged by the hub nut on the shaft.