Alternator: Service and Repair

GENERATOR ASSEMBLY

REMOVAL AND INSTALLATION

Pre-removal & Post-installation Operation:

Removal Steps 1-8:

REMOVAL SERVICE POINTS

[[A]] DRIVE BELT REMOVAL
To introduce the serpentine drive system with the drive belt auto-tensioner, the following operations will be required.

CAUTION
To reuse the drive belt, draw an arrow indicating the rotating direction on the back of the belt using chalk to install the same direction.








1. Rotate the pulley bolt of the drive belt auto-tensioner counter-clockwise with an offset wrench [recommendation: 45°, a long offset wrench (5/8 x 11 /16 inches)], and insert the hexagon wrench into the auto-tensioner hole to fix the auto-tensioner.
2. Remove the drive belt.

[[B]] A/C COMPRESSOR ASSEMBLY REMOVAL
1. With the hose installed, remove the A/C compressor assembly from the bracket.
2. Tie the removed A/C compressor assembly with a string at a position where it will not interfere with the removal and installation of the alternator assembly.

[[C]] GENERATOR ASSEMBLY REMOVAL
Move the A/C compressor assembly sideways, and remove the generator assembly to the downside.

DISASSEMBLY AND ASSEMBLY

Disassembly Steps 1-15:

DISASSEMBLY SERVICE POINTS

[[A]] PULLEY REMOVAL





1. Set the special tool MB992226 to the pulley.





2. Set the closed wrench to the hexagonal area of the special tool MB992226.





3. Insert the hexagonal bit socket having width across flats of 10 mm into the hexagonal area of the rotor shaft.
4. Hold the pulley with the closed wrench. Rotate the rotor shaft clockwise to remove the pulley.

[[B]] FRONT BRACKET REMOVAL

CAUTION

Do not insert the screwdriver blades too deep. Doing so could damage the stator coil.

Insert the blades of screwdrivers between the front bracket and stator core, and pry and separate them with the screwdrivers.

[[C]] STATOR / REGULATOR ASSEMBLY REMOVAL

CAUTION

^ Use a 180-250 W soldering iron, and finish unsoldering within four seconds. Diodes will be damaged by heat if unsoldering time is too long.
^ Avoid applying undue force to the diode leads.

1. Unsolder the stator leads from the main diode of the rectifier assembly when the stator is removed.
2. When removing the rectifier assembly from the regulator assembly, undo the soldered points on the rectifier assembly.

REASSEMBLY SERVICE POINTS

]]A[[ REGULATOR ASSEMBLY INSTALLATION








After installing the regulator assembly, insert a piece of wire through the hole in the rear bracket while pressing the brush to keep the brush against movement.

NOTE: Holding the brush with the wire facilities installation of the rotor.

]]B[[ ROTOR INSTALLATION





Remove the brush holding wire after the rotor has been installed.

]]C[[ PULLEY INSTALLATION
1. Clean the inner race of the front bearing and that of the pulley.








2. Screws the inner race of the pulley until it touches the inner race of the front bearing.





3. Set the special tool MB992226 to the pulley.





4. Set the closed wrench to the hexagonal area of the special tool MB992226.





5. Insert the hexagonal bit socket having width across flats of 10 mm (0.4 inch) into the hexagonal area of the rotor shaft.
6. Hold the pulley with the closed wrench. Rotate the hexagonal bit socket counterclockwise to tighten it to the specified torque.

Specified torque: 73±12 N-m (54±8 ft-lb)

INSPECTION

PULLEY





Lock the pulley when rotating it clockwise. Check that the pulley rotates smoothly when rotating it counterclockwise.

CAUTION
Locking the one-way clutch might cause the damaged drive belt and an abnormal noise.

ROTOR





1. Measure the resistance between the two slip rings of the rotor coil to check the continuity between them. Replace the rotor if the resistance is not within the standard value range.

Standard value: 2.1-2.4 Ohms

2. Check the continuity between the slip rings and core.





3. If continuity is present, replace the rotor.

STATOR





1. Check the continuity between coil leads. If there is no continuity, replace the stator.





2. Check the continuity between coil and core. If there is continuity, replace the stator.

RECTIFIER ASSEMBLY





1. Check the condition of the (+) heat sink by checking the continuity between the (+) heat sink and each of the stator coil lead connecting terminals.

If the continuity is present for both terminals, or if no continuity is present for both terminals, the diode is shorted. Replace the rectifier assembly.





2. Check the condition of the (-) heat sink by checking the continuity between the (-) heat sink and each of the stator coil lead connecting terminals.

If the continuity is present for both terminals, or if no continuity is present for both terminals, the diode is shorted. Replace the rectifier assembly.

BRUSH





1. Measure the length of the protrusion of the brush. Replace the brush if the protrusion length is shorter than the limit.

Limit: 2 mm (0.08 inch) minimum

2. Unsolder the lead of the brush. The brush will come out, becoming ready for removal.





3. Install a new brush by pushing it into the holder as shown in the drawing and soldering the lead.