WHEEL-REAR 3149710 - Caterpillar

Figure 20-Forcing snap ring over shaft.Field Coil Checks
The various types of circuits used are shown in the wiring diagrams of Figure 11. The field coils can be checked for grounds and opens by using a test lamp.
Figure 21-Forcing retainer over snap ring.Grounds-If the motor has one or more coils normally connected to ground, the ground connections must be disconnected during this check. Connect one lead of the 110-volt test lamp to the field frame and the other lead to the field connector. If the lamp lights, at least one field coil is grounded which must be repaired or replaced. This check cannot be made if the ground connection cannot be disconnected.Opens-Connect test lamp leads to ends of field coils. If lamp does not light, the field coils are open.Field Coil Removal
Field coils can be removed from the field frame assembly by using a pole shoe screwdriver. A pole shoe spreader should also be used to prevent distortion of the field frame. Careful installation of the field coils is necessary to prevent shorting or grounding of the field coils as the pole shoes are tightened into place. Where the pole shoe has a long lip on one side and a short lip on the other, the long lip should be assembled in the direction of armature rotation so it becomes the trailing (not leading) edge of the pole shoe.Clutch Assembly
Diassembly procedures for the various types of clutches are outlined below.A. Intermediate Duty Sprag Clutch. An early type clutch and late type clutch are shown in Figures 12 and 13.1. Remove the lock wire, collar, and jump spring from the sleeve assembly.2. Remove the spring stop washer and second lock wire from the early type clutch (Fig. 12).3. Remove the retainer ring and large washers. Do not remove the sleeve assembly or sprags from the shell assembly.4. Lubricate the sprags and saturate the felt washer with No. 5W20 oil. Heavier oil must not be used.5. Assembly is the reverse of disassembly.
Figure 22-Brush with offset hole assembled to brush arm.B. Heavy Duty Sprag Clutch and DR-250 Drive. An early type and a late type heavy duty sprag clutch are shown in Figures 14 and 15 and the DR-250 drive is shown in Figure 16.1. Remove the cupped pinion stop and split washer. In removing the cupped pinion stop, it will probably be damaged. A new one will be required at time of reassembly.2. Remove the other parts as illustrated.3. Do not lubricate the sprags on heavy duty clutches, as they are lubricated for life with special oil at the factory.4. Assembly is the reverse of disassembly.C. Spline Drive and Positork Drive. These types of drive assemblies are serviced by complete replacement only.
Figure 23-Circuit for checking pinion clearance. (Types shown in Figures 1, 2 and 3.)Solenoid Checks
A basic solenoid circuit is shown in Figures 17 and 18. Solenoids may differ in appearance but can be checked electrically by connecting a battery of the specified voltage, a switch, and an ammeter to the