LINK AS-SPRING 6D0475 - Caterpillar

FIG. 7 POSITIVE SIDE DIODE CHECK
FIG. 8 NEGATIVE SIDE DIODE CHECKCheck Of Stator Coil
To check the stator coil, it is not necessary to disconnect the rectifier wiring if the rectifier is in satisfactory condition. For accurate inspection, however, check the coil as shown in FIG. 9 thru FIG. 12.1. For continuity check, test between either pair of the three leads as shown in FIG. 9 or FIG. 10.
FIG. 9 STATOR CONTINUITY CHECK (4N4540 Alternator)
FIG. 10 STATOR CONTINUITY CHECK (6N5460 Alternator)2. For grounding check, test between any one of the leads and the core (or frame) as shown in FIG. 11 or FIG. 12.
FIG. 11 STATOR GROUND CHECK (4N4540 Alternator)
FIG. 12 STATOR GROUND CHECK (6N5460 Alternator)Check Of Rotor Coil
Check the field coil as follows:1. Continuity must exist between slip rings of rotor coil (FIG. 13).
FIG. 13 CONTINUITY CHECK OF ROTOR COIL2. Check for ground of field coil between the slip ring and core (FIG. 14).
FIG. 14 GROUNDING CHECK OF ROTOR COILCheck Of Brush Wear
The top of the brush is beveled. The height of the brush, therefore, should be checked at the center of the bevel surface (FIG. 15).
FIG. 15 CHECK OF BRUSH WEARCheck Of Slip Ring
FIG. 16 CHECK OF SLIP RINGUse #400 sandpaper to polish the surface of the slip ring.Disassembly
The 4N4540 Alternator is illustrated for Disassembly.
FIG. 17 SEPARATING THE ALTERNATOR1. Remove the three through bolts. Insert screwdrivers into the notches of the drive end frame. Separate the alternator into the drive and rear assemblies by tapping the end frame with a wooden hammer while prying with the screwdrivers (FIG. 17).
When prying with the screwdrivers, do not insert the screwdrivers too deep, otherwise a damaged stator coil results.
FIG. 18 LOOSENING THE PULLEY LOCK NUT2. With the rotor core held in a vise, loosen the pulley lock nut with box wrench (FIG. 18).
When holding the rotor core in the vise, be careful not to deform the core by tightening the vise too much.
FIG. 19 SEPARATING THE DRIVE ASSEMBLY3. Remove the pulley and fan. Pull out the drive end frame from the rotor shaft (FIG. 19).
FIG. 20 SEPARATING THE REAR ASSEMBLY4. Remove four nuts from the rear of the rear end frame. Remove the stator together with the rectifier (FIG. 20).
FIG. 21 SEPARATING THE RECTIFIER5. To separate the rectifier from the stator coils, quickly unsolder the connection by using a soldering iron (FIG. 21).
FIG. 22 UNSOLDERING WITH SOLDERING IRON
When unsoldering, hold the rectifier leads with long nose pliers to prevent the rectifier from being heated (FIG. 22).
Assembly
The 6N5460 Alternator is illustrated for Assembly.1. Remove oil, grease and dirt from alternator components.2. Solder the rectifier and stator leads with a soldering iron.
FIG. 23 SOLDERING THE LEADS
When soldering the rectifier leads, use long nose pliers to prevent heat damage to rectifier (FIG. 23).
FIG. 24 INSTALLING THE TERMINAL BOLT3. Check brushes for excess wear. When replacing a brush, solder the leads with the brush projected 1/2 in. (12.5 mm) from brush holder. After soldering, make sure that the brush moves in and out smoothly.Assemble